PB99-964601
EPA541-R99-036
1999
EPA Superfund
Record of Decision:
Fort Wainwright OU5
Fairbanks, AK
3/31/1999
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r . < • ff - -\
I • ••• ! i^^J
RECORD OF DECISION
for
OPERABLE UNIT 5
FORT WAINWRIGHT
FAIRBANKS, ALASKA
May 1999
ANCyTRM499 OOC/991030005
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DECLARATION STATEMENT
for
RECORD OF DECISION
FORT WAINWRIGHT
FAIRBANKS, ALASKA
OPERABLE UNIT 5
SITE NAME AND LOCATION
Operable Unit 5
Fort Wainwright
Fairbanks, Alaska
STATEMENT OF BASIS AND PURPOSE
This Record of Decision (ROD) presents the selected remedial actions for Operable Unit 5
(OU5) at Fort Wainwright near Fairbanks, Alaska. OU5 is identified as the final operable
unit in the Federal Facilities Agreement. OU5 includes three source areas deferred from
previously investigated operable units, as well as three source areas identified for inclusion
in OU5. Four source areas are identified for action: (1) three subareas of the West
Quartermaster's Fueling System (WQFS); (2) East Quartermaster's Fueling System (EQFS);
(3) Remedial Area 1A (also called the Birch Hill Aboveground Storage Tanks); (4) Open
Burning/Open Detonation (OB/OD) area. Two source areas are recommended for no
further action under the Comprehensive Environmental Response, Compensation, and
Liability Act of 1980 (CERCLA): (1) Former Explosive Ordnance Disposal (EOD) Range and
(2) Motor Pool Buildings. In addition, several petroleum-contaminated sites, including one
WQFS subarea, have been and are being addressed in accordance with an agreement
between the U.S. Army (Army) and the State of Alaska.
The ROD was developed in accordance with CERCLA, as amended by the Superfund
Amendments and Reauthorization Act of 1986 (42 United States Code, Section 9601 et seq.),
and to the extent practicable, in accordance with the National Oil and Hazardous
Substances Pollution Contingency Plan (40 Code of Federal Regulations 300 et seq.). These
decisions are based on the Administrative Record for this operable unit.
The Army, the U.S. Environmental Protection Agency, and the State of Alaska, through the
Alaska Department-of Environmental Conservation, concur with the selected remedies.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from the WQFS, EQFS, and Remedial
Area 1A source areas, if not addressed by implementing the response actions selected in
this ROD, may present an imminent and substantial endangerment to public health,
welfare, or the environment. Specific hazardous substances are bis(2-chloroethyl)ether,
1,2-dichloroethane, 1,2-ethylene dibromide, 1,1/1-trichloroethane, trichloroethene, benzene,
ethylbenzene, toluene, xylenes, lead, total aromatic hydrocarbons, and total aqueous
hydrocarbons.
ANC/TRM500 DOC/991030007 FINAL OU5 ROD I
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DESCRIPTION OF SELECTED REMEDIES
This is the fifth and final operable unit to reach a final-action ROD at the Fort Wainwright
National Priorities List site. This ROD addresses soil and groundwater contamination at
The remedies were selected to reduce or prevent risks to human health and the
environment associated with potential current or future exposure to the contaminants. The
remedial action objectives (RAOs) of this ROD are designed to perform the following:
• Prevent migration of WQFS and EQFS soil contaminants to groundwater
• Restore groundwater beneath the WQFS and EQFS to beneficial use of drinking water
within a reasonable time frame
• Reduce cancer and noncancer risks from exposure to volatile compounds and petroleum
in soil and groundwater of the WQFS and EQFS
• Minimize potential migration of WQFS contamination to the Chena River and
downgradient drinking water wells
• Remove WQFS floating product from the smear zone to the extent practicable
• Protect aquatic resources by reducing WQFS contaminant releases to the Chena River
• Prevent use of groundwater beneath the WQFS and EQFS that contains contaminants at
levels that exceed Safe Drinking Water Act levels
• Reduce risk to human health and terrestrial receptors from exposure to lead-
contaminated soil in Remedial Area 1 A.
The following are major components of the remedy selected for Subarea 1 of the WQFS
(WQFS1):
• In situ source-area treatment with air sparging and soil vapor extraction to attain state
and federal standards for drinking water
• Potential in-place soil heating at hot spots, pending results of a treatability study to
increase contaminant removal
• Potential operation of a downgradient air-sparging trench to prevent migration of
contaminants to the Chena River and potential downgradient receptors
The following are major components of the remedy selected for Subarea 2 of the WOFS
(WQFS2):
• Source-area treatment with air sparging and soil vapor extraction to attain state and
federal standards for drinking water
• Continued operation of the downgradient air-sparging curtain to prevent migration of
contaminants to the Chena River
• Groundwater monitoring to determine downgradient concentrations
ANOTRM500 00039,03X07
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The following is the major component of the remedy selected for Subarea 3 of the WQFS
(WQFS3):
• Source-area treatment with air sparging and soil vapor extraction to attain state and
federal standards for drinking water
The following is the major component of the remedy selected for EQFS:
• Continued operation of the air sparging and soil vapor extraction system at
Building 1060 to attain state and federal drinking water standards
All selected remedies for the EQFS and WQFS areas include the following:
• Institutional controls to restrict access, water use, and land use
• Monitored and evaluated natural attenuation
• Monitoring to determine achievement of RAOs
The major component of the remedy selected for Remedial Area 1A is as follows:
• Institutional controls to restrict access and land use
Other areas addressed under this ROD are the Chena River and the former OB/OD Area.
The Chena River Aquatic Assessment Program has been designed to determine whether
actual impacts to the Chena River have occurred, assess their significance, and measure
changes over time. Components of the program include the following:
• Collecting and analyzing water, sediment, and detritus
• Collecting and analyzing benthic macroinvertebrates
• Determining reductions of contaminant load into the Chena River
In addition, no further action is selected for the former OB/OD area for hazardous
chemicals. Because of concerns about potential human exposure to unexploded ordnance,
the Army has institutional controls that provide monitoring and control of access to the site.
These controls are required to remain in place. No analysis of remedial alternatives was
conducted for the OB/OD area. A discussion of the OB/OD area is provided in Section 9 of
this ROD.
STATUTORY DETERMINATION
The selected remedial actions are protective of human health and the environment, comply
with federal and state requirements that are legally applicable or relevant and appropriate
to the remedial actions, and are cost-effective.
The WQFS and EQFS remedies use permanent solutions and alternative treatment
technologies to the maximum extent practicable. They also satisfy the statutory preference
for remedies that employ treatments that reduce toxicity, mobility, and volume as a
principal element. Treatment of the principal threats of Remedial Area 1A use was not
found to be practicable; the remedy for Remedial Area 1A does not satisfy the statutory
preference for treatment as a principal element. The remedy is protective under existing
land-use scenarios and restricts exposure to human health and the environment.
ANC/TRM500.DOC/991030007 FINAL OU5 HOD III
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Because these remedies will result in hazardous substances above health-based levels
remaining at these source areas, a review will be conducted within 5 years after
commencement of remedial actions to ensure that the remedies continue to provide
adequate protection of human health and the environment.
IV FINAL OUS ROD
ANC/TRMSOO DOC/991030007
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SIGNATURE
Signature sheet for the foregoing Operable Unit 5, Fort Wainwright, Record of Decision
between the U.S. Army and the Environmental Protection Agency, Region 10, with
concurrence by the Alaska Department of Environmental Conservation.
R.L. Van Antwerp
Major General, USA
Assistant Chief of Staff for
Installation Management
U.S. Army
Date
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Vf
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SIGNATURE
Signature sheet for the foregoing Operable Unit 5, Fort Wainwright, Record of Decision
between the U.S. Army and the U.S. Environmental Protection Agency, Region 10, with
concurrence by the Alaska Department of Environmental Conservation.
?/t//99
Chuck Clarke Date
Regional Administrator, Region X
United States Environmental Protection Agency
ANOTRM282.DOC/982750007 FINAL OUS HOD VII
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SIGNATURE
Signature sheet for the foregoing Operable Unit 5, Fort Wainwright, Record of Decision
between the U.S. Army and the U.S. Environmental Protection Agency, Region 10, with
concurrence by the Alaska Department of Environmental Conservation.
,.-_ /
Lynn'ToW^Kent Date
Contaminated Sites Program Manager
Division of Spill Prevention and Response
Alaska Department of Environmental Conservation
ANC/TRM282.DOC/9827S0007 FINAL OU5 ROD VIII
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Contents
Section
Declaration Statement • "
* • *
Abbreviations X1U
Decision Summary DS-1
1 Site Description 1
1.1 Site Location and Description !
1.1.1 WQFSArea : 3
1.1.2 EQFS Area :. 4
1.1.3 Remedial Area 1A 4
1.1.4 OB/ODArea... • 4
1.1.5 Former EOD Range (Blair Lakes Alpha Impact Area) 5
1.1.6 Motor Pool Buildings - 5
1.2 Soils and Geology 5
1.3 Hydrogeology and Groundwater Use 5
1.4 Land Use . • • 6
2 Site History and Enforcement Activities 9
2.1 Site History..... - 9
2.1.1 WQFS Area • 9
2.1.2 EQFS Area : • n
2.1.3 Chena River • 12
2.1.4 Remedial Area 1A 13
2.1.5 OB/OD Area 13
2.1.6 No Further Action Sites 14
2.1.7 Two-Party Agreement Sites 15
2.2 Enforcement Activities -• ^
2.3 Highlights of Community Participation 16
2.4 Scope and Role of Operable Units 17
3 Summary of Source Area Characteristics 19
3.1 Transport Pathways and Hydrogeologic Conditions -—•19
3.1.1 Air Transport - 19
3.1.2 Surface Water Runoff • 19
3.1.3 Migration in Soil to Groundwater 19
3.1.4 Groundwater Migration • 20
3.1.5 Groundwater and Chena River Interaction 21
3.1.6 Sediment Transport 22
3.1.7 Potential Transport Pathways and Receptors 22
3.2 Nature and Extent of Contamination 22
3.2.1 WQFS Nature and Extent of Contamination 23
ANOTRM499 DOC/991030005. FINAL OU5 ROD IX
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CONTENTS
3.2.2 EQFS Nature and Extent of Contamination 26
3.2.3 Chena River -Q
3.2.4 Remedial Area 1A 2«
4 Summary of Site Risks
4.1 Human Health Risk Assessment ZZZ.Z... 31
4.1.1 Identification of Contaminants of Concern (Screening Analysis) 31
4.1.2 Exposure Assessment ; 32 *
4.1.3 Toxicity Assessment , 35
4.1.4 Risk Characterization 35
4.1.5 Uncertainty Analysis 40
4.2 Ecological Risk Assessment , ZZIZ... 45
4.2.1 Ecological Problem Formulation .....ZZZ.Z" 45
4.2.2 Ecological Risk Analysis " " 47
4.2.3 Ecological Risk Characterization 48
4.3 Risk Assessment Conclusions ZZZZ 50
5 Description of Alternatives 53
5.1 Need for Remedial Action... „
5.1.1 WQFS Area „
5.1.2 EQFS Area '-ZZZZZZZZ 53
5.1.3 Postwide Sampling at the Chena River 54
5.1.4 Remedial Area 1A Z'Z. 54
5.2 Remedial Action Objectives.... t-.
5.2.1 Soil ZZ""IZI""Z"Z" 54
5.2.2 Groundwater (WQFS and EQFS) ...ZZZ 55
5.2.3 Chena River Sediment and Surface Water ; 55
5.3 Significant Applicable or Relevant and Appropriate Requirements 55
5.4 Description of Alternatives 56
5.4.1 Development of Remedial Alternatives 56
5.4.2 Subarea WQFS1 Z" 59
5.4.3 Subarea WQFS2 Z.'Z" {.*
5.4.4 Subarea WQFS3 " ^
5.4.5 EQFS Source Area...; ZZ^Z"Z'ZZ"'"'ZZZi 70
5.4.6 Remedial Area 1A " 74
6 Summary of Comparative Analysis of Alternatives. 77
6.1 Subarea WQFS1
6.1.1 Threshold Criteria : ZZZ.! -78
6.1.2 Balancing Criteria 79
6.1.3 Modifying Criteria on *
6.2 Subarea WQFS2 ZZZ1 o
6.2.1 Threshold Criteria '. 8l
6.2.2 Balancing Criteria S1
6.2.3 Modifying Criteria so **
6.3 Subarea WQFS3 Z.ZZ o?
6.3.1 Threshold Criteria -ZZZZZZZZZZZZZZZZ 83
6.3.2 Balancing Criteria g3
6.3.3 Modifying Criteria
X FINAL OU5 ROD
ANC/TRM499.DOC/991030005
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CONTENTS
6.4 EQFS Source Area 85
6.4.1 Threshold Criteria 85
6.4.2 Balancing Criteria 86
6.4.3 Modifying Criteria 87
6.5 Remedial Area 1A 88
6.5.1 Threshold Criteria 88
6.5.2 Balancing Criteria 88
6.5.3 Modifying Criteria , 89
7 Selected Remedy. 93
7.1 Selected Remedies 93
7.1.1 Chena River Aquatic Assessment 93
7.1.2 Institutional Controls 94
7.1.3 Subarea WQFS1 95
7.1.4 Subarea WQFS2 97
7.1.5 Subarea WQFS3 98
7.1.6 EQFS Source Area 99
7.1.7 Remedial Area 1A 100
7.2 Remedial Action Goals 101
7.3 Five Year Review 105
8 Statutory Determinations 107
8.1 Protection of Human Health and the Environment 107
8.1.1 WQFS1, WQFS2, WQFS3, and EQFS 107
8.1.2 Remedial Area 1A 107
8.2 Compliance with Applicable or Relevant and Appropriate Requirements
and To-Be-Considered Guidance 108
8.2.1 Applicable or Relevant and Appropriate Description 108
8.2.2 Chemical-Specific Applicable or Relevant and
Appropriate Requirements 109
8.2.3 Location-Specific Applicable or Relevant and
Appropriate Requirements 110
8.2.4 Action-Specific Applicable or Relevant and
Appropriate Requirements 110
8.2.5 To-Be-Considered Information Ill
8.3 Cost Effectiveness 112
8.4 Use of Permanent Solutions and Alternative Treatment Technologies
or Resource Recovery Technologies to the Maximum Extent Practicable 1.12
8.5 Preference for Treatment as a Main Element 1 112
9 OB/ODPad 113
9.1 Site History 113
9.2 Physical Features 114
9.3 Nature and Extent of Contamination 114
9.4 Summary of Site Risks 115
9.5 OB/OD Area Closure 115
9.6 Closure Process 115
10 Documentation of Significant Changes.... 117
ANOTRM499 DOC/991030005 FINAL OU5 ROD XI
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CONTENTS
Appendix
A Responsiveness Summary
B Administrative Record Index
C No Further Action Sites and Fort Wainwright CERCLA Federal Facility
Agreement Recommended Actions
D Fort Wainwright Petroleum Strategy: Two-Party Agreement Sites and Fort
Wainwright CERCLA Federal Facility Agreement Recommended Action
E Operable Unit 5 Cost Estimates for Remedial Alternatives
Table
1 Summary of Soil and Groundwater Sample Results for Contaminants of
Concem-WQFS 23
2 Contaminated Soil Volume Estimates , 24
3 Summary of Soil and Groundwater Sample Results for Contaminants of
Concem-EQFS 27
4 Contaminants of Concern for Human Health Risk Assessment 32
5 Summary of Total Cancer Risks and Noncancer Hazard Indices for Potentially
Exposed Populations at WQFS 35
6 Summary of Total Cancer Risks and Noncancer Hazard Indices for Potentially
Exposed Populations at EQFS 37
7 Contaminants of Concern for the Chena River Based on Results of the
Postwide Risk Assessment 41
8 Contaminants of Potential Concern for the OU5 Ecological Risk Assessment 46
9 Remedial Alternatives for OU5 Source Areas 57
10 Criteria for Evaluation of Alternatives 77
11 WQFS, EQFS, and Remedial Area 1A Cost Comparison 90
12 Remedial Action Objectives and Preliminary Remediation
Goals for Operable Unit 5 102
Figure
1 Fort Wainwright Site Map with OU5 Areas 2
2 WQFS Subareas and EQFS Location Map .."' 3
3 Extent of Groundwater and Soil Contamination at OU5 24
4 Alternative 2 for WQFS1, WQFS2, WQFS3, and EQFS 59
5 Alternative 3 for WQFS1, WQFS3, and EQFS 60
6 Alternative 4 for WQFS1 ' 62
7 Alternative 5 for WQFS1 64
8 Alternative 3 for WQFS2 1"!.!""""!.'"""" 66
9 Alternative 4 for EQFS ', 72
10 Alternative 5 for EQFS ""!"".""" 73
XII FINAL OUS ROD ANC/TRM499.DOO991030005
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Abbreviations
AAC Alaska Administrative Code
ADEC Alaska Department of Environmental Conservation
AEHA U.S. Army Environmental Hygiene Agency
ARAR applicable or relevant and appropriate requirement
AS air sparging
AST aboveground storage tank
BTEX benzene, toluene, ethylbenzene, and xylenes
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act
CFR Code of Federal Regulations
COC contaminant of concern
COPC contaminant of potential concern
DCA dichloroethane
DCE dichloroethene
DDD dichlorodiphenyldichloroethane
DDE dichlorodiphenyldichloroethene
DDT dichlorodiphenyltrichloroethane
DRO diesel-range organic
EOD Explosive Ordnance Disposal
EPA U.S. Environmental Protection Agency
EQFS East Quartermaster's Fueling System
FFA Federal Facility Agreement
FFCA Federal Facility Compliance Agreement
FS feasibility study
GRO gasoline-range organic
MCL maximum contaminant level
MCLG maximum contaminant level goal
|ig/L micrograms per liter
mg/kg milligrams per kilogram
mg/L milligrams per liter
NCP National Oil and Hazardous Substances Pollution Contingency Plan
NFA no further action
NPL National Priorities List
O&M operation and maintenance
OB/OD Open Burning/Open Detonation
ANC/TRM499.DOC/991030005
FINAL OU5 ROD XIII
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ABBREVIATIONS
ORC
OU
OSWER
PAH
PCB
POL
ppm
PSD
QA
QFS
RAO
RBC
RCRA
RFA
RfD
RI
ROD
RPM
SARA
SOP
SVE
SVOC
TAH
TAqH
TBC
TCA '
TCE
TCLP
TS
USAF
USARAK
UST
UXO
VOC
WQFS
WQFS1
oxygen release compound
operable unit
Office of Solid Waste and Emergency Response
polynuclear aromatic hydrocarbon
polychlorinated biphenyl
petroleum, oil, and lubricants
parts per million
prevention of significant deterioration
quality assurance
Quartermaster's Fueling System
remedial action objective
risk-based concentration
Resource Conservation and Recovery Act
RCRA Facility Assessment
reference dose
remedial investigation
record of decision
remedial project manager
Superfund Amendments and Reauthorization Act of 1986
standard operating procedure
soil vapor extraction
semivolatile organic compound
total aromatic hydrocarbon
total aqueous hydrocarbon
to be considered
trichloroethane
trichloroethene
toxicity-characteristic leaching procedure
treatability study
U.S. Air Force
U.S. Army Alaska
underground storage tank
unexploded ordnance
volatile organic compound
West Quartermaster's Fueling System
WQFS Subarea 1
XIV FINAL OU5 ROD
ANC/TRM499.DOC/991030005
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ABBREVIATIONS
WQFS2 WQFS Subarea 2
WQFS3 WQFS Subarea 3
WQFS4 WQFS Subarea 4
ANC/TRM499.DOC/991030005 FINAL OU5 ROD XV
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ABBREVIATIONS
XVI FINAL OU5 ROD
ANOTRM499.00
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DECISION SUMMARY
RECORD OF DECISION
for
OPERABLE UNIT 5
FORT WAINWRIGHT
FAIRBANKS, ALASKA
This Decision Summary provides an overview of the problems posed by the contamination
at the Fort Wainwright Operable Unit 5 (OU5) source areas. This summary describes the
physical features of the site, the contaminants present, and the associated risks to human
health and the environment. The summary also describes the remedial alternatives
considered at OU5 source areas, provides the rationale for the remedial actions selected,
and states how the remedial actions satisfy the Comprehensive Environmental Response,
Compensation, and Liability Act of 1980 statutory requirements.
The United States Army completed a Remedial Investigation (RI) at OU5 to provide
information regarding the nature and extent of contamination in the soils and groundwater.
A baseline Human Health Risk Assessment and Ecological Risk Assessment were
developed and used in conjunction with the RI to determine the need for remedial action
and to aid in the selection of remedies. A Feasibility Study was completed to evaluate
remedial options.
ANC/TRM500.DOC/99t030007
FINAL OU5 ROD OS-1
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DECISION SUMMARY
DS-2 FINAL OU5 ROD
ANC/TRM500.00C/991030007
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SECTION 1
Site Description
•i-
1.1 Site Location and Description
Fort Wainwright is in the Fairbanks North Star Borough in central Alaska and covers about
918,000 acres on the east side of the City of Fairbanks (Figure 1). Fort Wainwright includes
the main post area, a range complex, and two maneuver areas. Fort Wainwright originally
was established in 1938 as a cold-weather testing station. During World War n, it served as
a crew and supply transfer point for the U.S. Lend-Lease program to the Soviet Union. After
the war, it became a resupply and maintenance base for the remote Distant Early Warning
sites, an experimental station in the Arctic Ocean, and the Nike Hercules missile sites in
Interior Alaska. In 1961, all operations were transferred' to the U.S. Army.
Primary missions at Fort Wainwright include training infantry soldiers in the arctic
environment, testing of equipment in arctic conditions, preparation of troops for defense of
the Pacific Rim, and rapid deployment of troops worldwide. Onsite industrial activities
include the operation, maintenance, and repair of fixed-wing aircraft, helicopters, tactical
and nontactical vehicles, weapon systems, as well as general support activities. The
activities also include power generation; steam heat production; drinking water production,
treatment, and distribution; and standby power and water production.
The Fort Wainwright cantonment area is 4,473 acres east of downtown Fairbanks, partly
within the city limits. The rest of Fort Wainwright consists of ranges and military maneuver
areas. The Chena River flows through Fort Wainwright and the City of Fairbanks into the
Tanana River. All source areas, except Remedial Area 1 A, are in a 500-year floodplain.
Remedial Area 1A, is 500 to 750 feet above mean sea level on the side of Birch Hill. No
threatened or endangered species reside in the OU5 area. The Ladd Field National
Historic/Landmark District is within the EQFS.
A number of sites associated with known or suspected releases of hazardous chemicals have
been identified across Fort Wainwright. Depending on the nature and extent of
contamination identified during preliminary site assessment activities, these sites have been
addressed as follows:
• Incorporated into one of the five operable units (OUs) on Fort Wainwright
• Identified as sites with petroleum, oil, and lubricants (POLs) for disposition under the
Two-Party Agreement between the Alaska Department of Environmental Conservation
(ADEC) and the Army
• Identified as no further action (NFA) sites under the Comprehensive Environmental
Restoration, Compensation, and Liability Act (CERCLA)
OUS is the final OU to be investigated at Fort Wainwright; consequently, this ROD
integrates the remaining evaluations at the post. Consideration of OUS includes potential
cumulative human health or ecological risks that may become evident from the aggregate of
ANC/TRM501.DOO991030010 FINAL OUS ROD 1
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SITE DESCRIPTION
Remedial Area 1A
(in Birch Hill Tank Farm)
Former Location of
Motor Pool
Building\
City
of
Fairbanks
GaffrteyRd.
I Motor Poql Motor Pool Motor Pool \ /
(Buildino Building \,-
'-•wj-na-r- HAVE. J~
Motor Pool ''x / /;
y—Building 3479 V /
//
.. 'Motor Pool
:.:' Building 3487
Motor Pool 'i
Building 3485 "
Chena River Aquatic Assessment Former EOD Range ~"''
Sampling Segments and OB/OD Area ''/
Figure 1. Fort Wainwright Site Map with OU5 Areas
2 FINAL OU5 ROD
ANC/TRM501 .DOC/991030010
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SITE DESCRIPTION
source areas and areas not otherwise resolved in previous OUs. OUS also has been used to
integrate all the remaining sites not addressed under one of the records of decision (RODs)
for OUs 1 through 4. OUS includes three source areas deferred from previous investigations
and three source areas originally identified in OUS:
• West Section, Former Quartermaster's Fueling System (WQFS)
• East Section Former Quartermaster's Fueling System (EQFS)
• Remedial Area 1A
• Open Burning/Open Detonation (OB/OD) Area
• Former Explosive Ordnance Disposal (EOD) Range (Blair Lakes Alpha Impact Area)
• Motor Pool Buildings
The locations of the WQFS, EQFS, Motor Pool buildings, Remedial Area 1A, and OB/OD
areas are shown in relation to the entire installation and the Chena River in Figure 1. This
ROD describes alternatives for remedial action for four of the six source areas: three
subareas in WQFS, EQFS, Remedial Area 1A, and the OB/OD Area. The other two source
areas have been identified as NFA sites under CERCLA.
1.1.1 WQFS Area
The WQFS (Figure 2) area covers approximately 50 acres between Taxiway 18 and the
Chena River.
Activities within this historical vehicle and aircraft maintenance operations area included
the use and disposal of solvents and other cleaning and maintenance compounds. Several
compounds of the Quartermaster's Fueling System (QFS) were located within the source
area. The WQS included underground storage tanks (USTs), aboveground storage tanks
Former
Retaining Struct
:.-=_=r-=^' '.1.565i
Front Street
v v Building 1599
•-.V— Foundation
laxwyay i(i_ ,
Figure 2. WQFS Subareas and EQFS Location Map
ANOTRM50I .DOC/991030010
FINAL OUS ROD 3
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SITE DESCRIPTION
(ASTs), a pump house and fueling islands, which have been removed. In addition, drains
were connected to a wooden pipe that drained to the river. The underground fuel pipelines
and a network of aboveground and buried fuel piping were abandoned in place, and the
status of the other buried piping, whether removed or abandoned, is unknown.
As shown in Figure 2, the WQFS area was divided into four subareas: WQFS1, WQFS2,
WQFS3, and WQFS4. The alternatives selected for WQFS1, WQFS2, and WQFS3 are
described in this ROD; WQFS4 is being addressed under the separate Two-Party Agreement
between the Army and the ADEC (Appendix D).
1.1.2 EQFSArea
The EQFS area covers approximately 40 acres between Taxiway 18 and the Chena River,
and between Building 1579 to the southwest and Building 1054 to the northeast (Figure 2).
The EQFS has been used for vehicle storage and maintenance, dry cleaning, fuels testing,
refueling, pesticide storage and mixing, and waste storage. In addition, drains were
connected to a wooden pipe that drained to the river. Solvents, pesticides, and petroleum
contamination were found in EQFS groundwater. Suspected sources include spills and leaks
from pipelines, fueling stations, and undocumented spills. The fuel pipeline has been
abandoned in place, and the status of the other buried piping, whether removed or
abandoned, is unknown.
The EQFS included USTs, ASTs, a pump house, and fueling islands, which have been
removed. The 8-inch-diameter fuel pipeline is abandoned, but is still in place; it is unknown
whether the other identified buried piping has been abandoned or removed.
1.1.3 Remedial Area 1A
Remedial Area 1A, the Birch Hill Tank Farm, is in the northwest corner of the main
cantonment area. It was constructed in 1943 and stored fuel for military use. In 1993, the
tanks were emptied and cleaned. The ground is almost entirely covered with vegetation.
Fuel stored in the tanks included arctic-grade diesel fuel, aircraft turbine and jet engine fuel
(JP-4), vehicle motor gasoline, and unleaded regular motor fuel. Tank maintenance activities
included cleaning sludge out of tank bottoms, the use of red lead pipe dope on bolts as a
thread lubricant, and tank painting.
1.1.4 OB/OD Area
The OB/OD area is within the active small-arms impact area, approximately 1,000 feet north
of the Tanana River and 1,500 feet south of the flood control dike. The site is along the east
side of a gravel borrow pit filled with water.
The OB/OD area reportedly was used by the Army and the U.S. Air Force (USAF) for
disposing of unexploded ordnance (UXO), unused propellants (black powder), rocket
motors, small-arms ammunition, and other hazardous materials. The site was used as an
OB/OD area from the mid-1960s through 1986.
4 FINAL OUS ROD ANC/TRM501.DOC/991030010
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SITE DESCRIPTION
1.1.5 Former EOD Range (Blair Lakes Alpha Impact Area)
The Former EOD Range is south of the other OU5 sites and reportedly lies somewhere
within the active firing range (see Figure 1). The physical description of this site matches the
location of the OB/OD area, and they are likely one and the same. This site formerly was
known as the Blair Lakes Alpha Impact Area. The Army and USAF reportedly used the
Former EOD Range as an open burning/open detonation site for disposing of UXO, unused
explosives, and motors that propel weapons, and ammunition for small firearms. The site
was active from the 1950s through 1974
1.1.6 Motor Pool Buildings
The Motor Pools are vehicle-maintenance facilities located at building 1053,1054,1168, 3015,
3421, 3425,3479,3485, and 3487. Buildings 3421,3425,3479, and 3485 each contain two
motor pools. With the exception of Building 1168, these buildings still operate as motor
pools. Minimal amounts of POL were stored at the Motor Pool Buildings. The motor pools
have been addressed as one source area to allow for a comprehensive motor pool
investigation.
1.2 Soils and Geology
Most of Fort Wainwright lies in the lowlands of the basin surrounding the Tanana and
Chena rivers, which has a surficial layer of fine-grained soil over deeper alluvial deposits.
The surface soil is generally less than 5 feet thick. The alluvial floodplain deposits tinder the
surface soil have varying proportions of sand and gravel, which are commonly layered. The
alluvium layers contain up to 10 percent silt. The area has discontinuous permafrost of
generally low ice content in mineral soil. The south-facing slopes of Birch Hill are free of
permafrost. North of the Chena River, the permafrost is pervasive, with large areas frozen
beneath a shallow active layer of 10 feet or less in the unconsolidated deposits. Thaw
channels are associated with old river meanders, and in some areas (primarily cleared
areas), the permafrost has receded to more than 20 feet below ground surface. Much of the
native vegetation has been removed near the military facilities south of the Chena River,
and the land surface has been extensively reshaped. Permafrost has degraded here to the
extent that no significant amount remains in WQFS or EQFS.
1.3 Hydrogeology and Groundwater Use
The main aquifer at Fort Wainwright is the Tanana basin alluvium. The aquifer ranges from
a few feet thick at the base of Birch Hill to at least 300 feet thick under the cantonment, and
may reach 700 feet thick in the Tanana River valley. The aquifer is unconfined in
permafrost-free areas. The water table is generally within 10 to 15 feet below ground surface
and generally flows west-northwest on the south side of the Chena River. Although
information on groundwater flow on the north side of the Chena River is limited, the flow
appears to be to the west-southwest, and is highly influenced by permafrost. The
groundwater at OU5 flows into the Chena River either in OU5 or downriver. The Chena
River flows through Fort Wainwright and the City of Fairbanks, into the Tanana River. The
Tanana River flows south of the containment area of Fort Wainwright.
ANC/THM501.DOO991030010 FINAL OU5 HOD 5
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STTE DESCRIPTION
Groundwater levels and flow near the Chena River fluctuate greatly with changes in the
river stage and interactions with the Tanana River. Typically, groundwater levels are
highest during spring breakup and late summer runoff, when the river flow is greatest and
river water enters the river banks. The groundwater flow also may be affected by high-
volume pumping at off-post gravel pits for dewatering activities.
Potable water at Fort Wainwright and Fairbanks is supplied only by groundwater. A single
distribution system supplies about 95 percent of potable water at Fort Wainwright. The post
is fed by two large-capacity wells in Building 3559, near the power plant. These wells were
completed at a depth of about 80 feet and provide between 1.5 million and 2.5 million
gallons of water per day to the water treatment plant for treatment and distribution. Five
emergency standby supply wells are located around the cantonment. These wells are
between 80 and 120 feet deep, and can provide 250,000 gallons per day per well. These wells
can supply minimally treated water to Fort Wainwright system for potable water supply.
The City of Fairbanks uses the same aquifer and has four developed wells in its Fairbanks
Municipal Utility System wells 1 mile downgradient of the post boundaries, on the banks of
the Chena River. These wells are the main drinking water supply for the city.
The Chena River is a clear-water (nonglacial) stream characterized in its lower reaches by
slough-like conditions, relatively slow-moving water, and a single, well-defined channel.
The river forms the boundary of Fort Wainwright for about 1.25 miles along WQFS and
EQFS. Approximately 2.5 miles downstream of OU5, the Chena River leaves military lands,
running through the City of Fairbanks to it confluence with the Tanana River, which is
about 11 miles downstream.
River engineering projects have significantly affected the hydrology and ecology of the
lower Chena River. Before 1941, the lower Chena River was a slough of the Tanana River
called the Chena Slough. In 1941, a dike was constructed across the upstream end of Chena
Slough to prevent floodwaters of the Tanana from causing flood damage to Fairbanks. The
Chena River is now the main source of flow through Fort Wainwright and Fairbanks. The
ecology of the lower Chena River has changed considerably since the exclusion of the glacial
meltwater of the Tanana River with its high load of suspended sediments. The flood control
program was expanded from 1975 to 1981.
Upstream of Fort Wainwright, the Chena River is fed by small streams from adjacent hills.
In Fort Wainwright, drainage from the main cantonment area drains into the south side of
the Chena River. In contrast, drainage north of the river on post is undeveloped, forested,
and contains a few gravel roads.
1.4 Land Use
Current land use for OU5 is light industrial; there are no residences in the OU. The nearest
residences, within 1 mile northeast of EQFS, are site housing on North Post. Another
residential area exists about 1 mile west of WQFS and 1.5 miles south of Remedial Area 1A.
Each residential area includes a school. Access to WQFS and EQFS is unrestricted.
Recreation in the area is encouraged currently with a bike trail as well as unlimited access to
the Chena River.
6 FINALOUS ROD ANOTRMSOI.DOC/991030010
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SITE DESCRIPTION
Groundwater in the aquifer that extends under the source areas is the sole source of
drinking water for Fort Wainwright and the City of Fairbanks. Wildlife use of the OU5 is
limited by loss of habitat resulting from facility activities.
ANOTRM501 .DOC/991030010
FINAL OU5 ROD 7
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StTE DESCRIPTION
8 FINAL OU5 ROD
ANOTRM501.DOO991030010
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SECTION 2
Site History and Enforcement Activities
2.1 Site History
2.1.1 WQFS Area
Before the early 1970s/ spills were not reported. The WQFS was the major industrial area for
the installation between the late 1930s and the late 1960s. Historical air photographs indicate
that numerous maintenance and industrial facilities existed in this area; all buildings have
been removed. Historical routine maintenance practices involved the use of solvents and
other hazardous materials. Disposal practices included pouring the materials down dry
wells, into leach fields, and onto the ground.
The 1996 Operable Unit 5 Remedial Investigation Report, Fort Waimvright, Alaska, lists recorded
spills from vehicle and aircraft maintenance operations and leaks, including a 1971 leak of
about 30,000 gallons of diesel fuel. The fuel reportedly ran into the abandoned wooden
sewer line that had an outfall at the Chena River. An estimated 1,600 gallons were
recovered; about 7,500 gallons were burned; and the rest was lost. Another 1971 spill of
about 16,000 gallons of gasoline occurred during fuel transfer activities. The fuel leaked into
the Chena River through the same wooden sewer line. In 1980, a fuel leak into the Chena
River occurred near WQFS. The source was unknown, but the 8-inch pipeline along the
north side of Gaffney Road was suspected. The Army dug a trench between Apple Road
and the river to capture the spill, and installed a sheet-metal retaining structure to prevent
fuel migration to the river. However, sheens had been observed in the river below the
retaining structure. In spring 1998, about 700 cubic yards of contaminated soil and the
retaining structure were removed. The removal action is discussed further in Section 5.4.3.
Building 1599, the facilities engineer maintenance shop, was built in 1942. It was burned in a
training exercise in 1994, leaving the concrete foundation. A 3-inch pipe extended from the
floor drain in the vehicle wash rack led to a manhole in the lubrication and service room,
where it passed through a grease trap and then out of the building into a septic tank.
Building 1599 also was used to store and mix pesticides before 1973. The building was
adjacent to a sewer terminating at an outfall into the Chena River. The end of the 6-inch
wooden pipe is still visible from the bank of the river. It is unknown if the building was
connected to this sewer line. However, sampling of the Chena River was conducted to
determine if any waste releases had occurred.
Several 55-gallon steel drums containing a black, sticky, tar-like substance were exposed
along the south bank of the Chena River within WQFS during the 1994 North Airfield
groundwater investigation. These drums were corroded, at least partially crushed, and
leaking into the soil, sediment, and surface water.
The exposed drums were removed in 1995 by the Fort Wainwright Department of Public
Works. Nine nearby buried drums and approximately 3 cubic yards of waste soil were
excavated and removed in 1996 during the OU5 remedial investigation (RI).
ANOTRM501 DOC/991030010 RNALOU5ROO 9
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SITE HISTORY AND ENFORCEMENT ACTIVITIES
Several treatability studies have been initiated at WQFS to evaluate the implementability,
effectiveness, and cost of potential remedial technologies to treat solvent and other volatile
organic commingled plumes. Treatability studies were designed to be incorporated into
final remedies if they proved to be successful. Effective technologies have been incorporated
into alternatives for WQFS and EQFS, as described below.
Treatability Study of Soil Vapor Extraction (SVE) and Air Sparging (AS) with Horizontal
Wells at WQFS1. This treatability study system includes the installation of a pilot-scale
treatment system that uses horizontal SVE/AS wells, instead of standard vertical wells, to
treat residual contamination in soil and ground water. The primary objective of this study is
to compare the cost-effectiveness and efficiency of wells drilled horizontally with vertical
wells drilled by conventional drilling. Fewer horizontal wells are needed than vertical wells,
which results in lower cost. The wells were installed in August 1997, and will be
incorporated into the selected remedy for WQFS1. The SVE well appears to be performing
as specified. Improvements to the AS well are currently being evaluated to enhance the
movement of air through the soil.
AS Curtain Treatability Study with Vertical AS Wells for Removal of Contaminants from
Groundwater Downgradient of WQFS2 Soil Source. This treatability study system will
demonstrate the applicability and cost-effectiveness of a vertical AS well curtain for
protection of the Chena River from contaminants. The AS curtain system consists of a row of
AS wells perpendicular to the groundwater flow direction. Air is injected into the AS wells
through piping with an air-compressor blower. The injected air displaces groundwater from
the largest, interconnected pores in the soil, forming continuous air channels. The curtain
was installed during the late summer of 1998 and operation started shortly after installation.
The system is expected to be in operation until cleanup objectives are achieved. This study
has been incorporated into Alternative 3 for WQFS2.
AS Trench Treatability Study. The objective of this study is to evaluate the effectiveness of
an AS trench on a laboratory scale. A short section of a simulated trench was installed In the
laboratory to evaluate backfill design and the operational properties of the trench. This
information would be used to evaluate effectiveness and to provide input on trench design.
Source Strength Treatability Study. The objective of this study is to assess the extent to
which contaminants present in floating product dissolve into groundwater. This treatability
study is being performed in WQFS1 and began in early 1998. Information will be
incorporated into groundwater modeling simulations to further refine fate and transport
prediction for use in design and operation of treatment systems.
WQFS Natural Attenuation Treatability Study. The objective of this study is to evaluate
the rate of contaminant disappearance and the mechanisms and processes for natural
attenuation in groundwater emanating from the WQFS1 source. Computer modeling will be
performed and soil and groundwater samples will be collected to determine the mechanism
of natural attenuation. This information is used to refine time frames for achieving remedial
action objectives (RAOs), to determine treatment system placement, and to better
understand the potential for downgradient migration of contaminants. Monitored and
evaluated natural attenuation has been incorporated into all active treatment remedies for
WQFS alternatives.
10 F1NAIOUSROD ANOTRM501.00O991030010
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SITE HISTORY AND ENFOOCEUENT ACrnvmES
Treatability Study of In Situ Soil Heating in WQFSl. This study will evaluate the extent to
which soil heating increases remediation rates through increased contaminant volatility and
biodegradation, which reduce the duration of treatment and decrease the level of residual
soil contamination. In situ soil heating with radio frequency will be compared to heating
with the six-phase technology. Both systems began operation in spring 1998. Six-phase
heating operated through November 1998. The radio-frequency treatability study system
was expected to be in operation until March 1999. In situ heating has been incorporated into
Alternatives 4 and 5 for WQFSl.
In Situ Treatability Study with Oxygen Release Compound (ORC) for Groundwater at
Subarea WQFS2. A pilot-scale ORC system was constructed and completed in 1996. A
formulation of magnesium peroxide contained in filter "socks" was inserted into the
groundwater wells, to allow contact with contaminated groundwater. The peroxide formula
was intended to increase dissolved oxygen in groundwater to enhance biodegradation
processes through more available oxygen. Performance was measured by the amount of
dissolved oxygen in groundwater. Groundwater sampling and dissolved-oxygen testing
were conducted quarterly. Sampling began in February 1997, and was expected to run
through mid-1998. Preliminary results received indicate that levels of dissolved oxygen
have not increased measurably. ORC will not be considered for expansion at OU5 because
preliminary results indicate that ORC may not be effective at reducing dissolved
contaminants in site groundwater. These wells are being used in conjunction with other
treatability studies.
Bench-Scale Column Study of Factors Limiting the Bioremediation Rate. Soil samples
have been collected throughout the OU5 source areas and will be used in this study. The
study started in January 1998 and is expected to continue until December 1998. Data
collected will be used to assess the bioremediation component of the selected remedial
actions and to refine estimated time frames for achieving RAOs.
2.1.2 EQFS Area
According to the OU5 RI report, EQFS has been used for vehicle storage and maintenance,
dry cleaning, fuels testing, refueling, pesticide storage and mixing, and waste storage (for
example, polychlorinated biphenyl [PCB] transformers, chemicals, paints, oils, brake fluid,
and solvents). The Motor Pool (Building 1054) had drains connected to a 6-inch pipe
connected to an 8-inch wooden pipe that drained to the river. Contamination from
commingled solvent and other volatile organic plumes was found in EQFS groundwater.
Historical routine maintenance practices involved the use of solvents and other hazardous
materials. Disposal practices included pouring the materials down dry wells, into leach '
fields, and onto the ground. Soil and groundwater beneath Building 1054 were investigated
during an OU1 preliminary source evaluation. On June 3,1994, the remedial project
managers (RPMs) recommended NFA under CERCLA for soil at Building 1054 (Fort
Wainwright CERCLA Federal Facility Agreement Recommended Action, Source Area: Building
1054). Under the same decision document, groundwater beneath Building 1054 was referred
from OU1 to the EQFS area of OU5.
Ongoing treatability studies at EQFS are described below.
ANCVrRM501.DOC/99t030010 FINAL 01)5 ROD 11
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SITE HISTORY AND ENFORCEMENT ACTIVITIES
SVE/AS System at Building 1060. Consisting of nine SVE and eight AS wells, this system
was installed at the Building 1060 site in June 1994 to evaluate the suitability of using these
technologies to remediate solvent- and petroleum-contaminated groundwater and soils. The
system has run almost continuously since startup. The treatability study has demonstrated
that the SVE/AS system at Building 1060 is successfully removing chlorinated solvents and
petroleum hydrocarbons from the soils and groundwater. This treatability study system was
incorporated into Alternatives 2, 3, 4, and 5 for EQFS.
Natural Attenuation Treatability Study. In this treatability study, monitoring wells were
installed around the contaminant plume. In addition, contaminant and geochemical data
were collected. Contaminant concentrations were modeled to simulate the migration and
attenuation of the contaminant plume through time. A simplified risk assessment of
exposure to groundwater contamination through seepage to the Chena River also was
conducted. The objective of this study is to evaluate the rate of contaminant disappearance
and the mechanisms and processes for the natural attenuation of groundwater emanating
from the EQFS source. Historical trends showed a reduction in hydrocarbon concentrations
in all EQFS wells downgradient of the source, and contaminant mass calculations showed
an overall decrease in total mass over time. Because natural attenuation has been
successfully demonstrated in EQFS, monitored and evaluated natural attenuation has been
incorporated into all alternatives for EQFS, with the exception of the no-action alternative.
2.1.3 Chena River
The Chena River was identified as the area most likely to be affected by multiple source
areas. As a result, the Chena River Aquatic Assessment Program was initiated to evaluate
potential impacts. A total of 81 known or suspected contaminated sites were identified for
consideration in the postwide risk assessment. To assess risks to aquatic receptors in the
Chena River, five segments of the river (Segments A through E) that correspond to the
spatial distribution of river sediment and surface water samples were identified. These
segments are also adjacent or linked to the following source areas:
• Segment A-Channel B outflow (a ditch draining contaminated areas assigned to OU1
and OU2) and the Chena River Tar Site
• Segment B-Engineer Park Drum Site
• Segment C-North Post Site (assigned to OU2) and Landfill (assigned to OU4)
• Segment D-WQFS and EQFS (assigned to OU5), Railcar Off-loading Facility (assigned to
OU3), and 801 Drum Burial Site (assigned to OU1)
• Segment E-the Glass Park Tar Site
When average concentrations of chemicals in each segment were compared to the
appropriate benchmark values for toxicology of surface water and sediment, a number of
exceedances were noted. The following compounds exceeded benchmark levels: DDT or its
metabolites, dioxins, furans, several polynuclear aromatic hydrocarbons (PAHs), pesticides,
and PCBs. Surface water benchmarks were exceeded for a number of chemicals in Segment
D. The impacts of these exceedances are discussed further in Section 4, Risk Assessment.
12 FINAL OU5 ROD ANC/TRM501.DOC/991030010
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SITE MSTOflY AND ENFOBCEUEMT ACTIVITIES
Results of groundwater sampling show that contaminated groundwater from the WQFS
area meets the Chena River in Segment D. Seepage from within this area often creates a
visible sheen on the river, and contaminated sediment along the shore releases a
hydrocarbon sheen and odor.
The Chena River is listed as a water-quality-limited water body, according to Section 303(d)
of the Clean Water Act. Tier II lists the river as a water body for which an assessment has
been completed and that now requires a water-body recovery plan. Water-quality-limited
water bodies are surface waters with documentation of actual or imminent persistent
exceedances of water quality criteria and/or adverse impacts to designated uses.
Designation of a water body as a water-quality-limited water body does not necessarily
indicate that the entire water body is affected. In most cases, only a segment of the water
body is affected. The Chena River was included on the list in 1994 because of turbidity,
sediment, and habitat modification. However because the turbidity and sedimentation may
be the result of a one-time failure of a settling pond for placer mining, which has been
repaired, the Alaska Mining Division has recommended that the turbidity and sediment
parameters be dropped. ADEC recommends that the Chena River be included on the list
because of petroleum products.
2.1.4 Remedial Area 1A
Remedial Area 1A was investigated in the OU3 RL The soil contamination in the top tank
area was transferred to OU5 for further evaluation in the January 1996 Record of Decision for
Operable Unit 3, Fort Wainwright, Fairbanks, Alaska, to provide time to select an appropriate
cleanup level for lead-based paint in soil. National cleanup standards specific to lead-based
paint in soil have not yet been promulgated. Since the OU3 ROD was signed, new
information indicating additional sources of lead in soil at Remedial Area 1A has become
available. Records on historical tank farm activities indicate that the suspected origins of
lead contamination in soils include sludge from the bottoms of tanks, lead-containing thread
lubricant used on bolt threads for routine maintenance, and leaded paint chips from tank
maintenance. Soil is contaminated with lead, petroleum, and related constituents.
Groundwater investigation on Birch Hill has been limited in scope because of the difficulty
in drilling with the tanks in place, the fractured rock composition, and the slope and terrain
of the tank farm. Petroleum spills have occurred in and around the tanks and the truck fill
stand throughout the history of the fuel terminal. Petroleum contamination at Fort
Wainwright is primarily addressed through the conditions of the Two-Party Agreement
between the State of Alaska and the Army. Groundwater at the base of Birch Hill is
contaminated with commingled volatile organic compounds (VOCs) and is being addressed
under OU3.
2.1.5 OB/ODArea
The OB/OD area, previously referred to as the EOD area, is within the active small-arms
impact range on Fort Wainwright. Open burning and open detonation of explosives on Fort
Wainwright historically have been performed on this pad from the mid 1960s to some time
between 1981 and 1986. No OB/OD activities have been performed on OB/OD pad since
that time. The pad now contains no visible debris.
ANC/THM501 .DOC/991030010
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StTE HSTORY AND ENFORCEMENT ACTIVmES
The OB/OD area, which was designated as a RCRA-regulated unit, was scheduled for
j^6^ TUIe 4°'Part 265f of ^ 4° Code °f Fed<*«l Regulations (CFR) 265, Subparts G
and P. This area was included in OU5 under the FFA. The process for closing the OB/OD
pad in accordance with RCRA regulations is detailed in Section 9 of this ROD.
An RI at the OB/OD area in 1996 included sampling and analysis of soil. Further details of
this investigation are described in Section 9 of this ROD. The ecological and human health
nsk assessments completed during the RI indicate that the risks are very low. For this
reason, the OB/OD area has been recommended for NFA.
Public access to the OB/OD area is restricted. Entry into this area is by a road with a locked
gate. Access is controlled and monitored by the Range Control at Fort Wainwright These
restrictions are not expected to change. Because of the potential for hazard from UXO in this
area, the OB/OD area is not available for future development. The OB/OD Area is
discussed extensively in Section 9 of this ROD.
2.1.6 No Further Action Sites
Two source areas are recommended for NFA under CERCLA: Former EOD Range and
Motor Pool Buildings. These sites are briefly discussed below. Appendix C provides an
illustration of these sites and other relevant information. No costs are associated with these
sites, and they are not discussed further in this ROD.
2.1.6.1 Former EOD Range
The Former EOD Range (Blair Lakes Alpha Impact Area) was referred from OU1 to OU5 on
January 13,1994, in the document No Further Action Site Summaries, OU1 Fort Wainwright
(1994). The source area was reportedly used as an OB/OD site for disposing of UXO and
dud ordnance through 1974. The extent of use and actual years of operation are unknown.
Fort Wainwright and contract personnel evaluated aerial photographs and historical
information, interviewed individuals with an institutional knowledge of Fort Wainwright
conducted site visits, and reviewed analytical data. The results of these efforts failed to
Pur°™e,a location of this Potential source area. It is believed that the former EOD Area and
the OB/OD Area are the same site.
On the basis of the inability to locate the Former EOD Range, it was determined that further
investigation of this source area under CERCLA was not justified. On April 10 and 25,1995
!?.! Army'EPA'and ADEC Pr°ject managers recommended NFA for this source under
CERCLA. NFA recommendations become final upon signature of this ROD.
2.1.6.2 Motor Pools •
The Motor Pool Buildings were referred to OU5 from OU1 in the 1996 Fort Wainwright
CERCLA Federal Facility Agreement Recommended Action, Source Area: Motorpools (13 Estimated)
to allow for a comprehensive investigation of the facilities. Table C-l in Appendix C lists the
Motor Pool Buildings and describes their facilities and current status.
The contaminants found at the Motor Pools were primarily low-level concentrations of POL
and solvents. After limited investigation, all Motor Pool source areas were recommended
for NFA under CERCLA. On July 27,1995, the Army, EPA, and ADEC project managers
14 FINAL OU5 ROD
ANOTRM501.DOC/991030010
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SITE HfSTOfty AND ENFORCEMENT ACTJVmES
recommended NFA for this source under CERCLA. NFA recommendations become final
upon signature of this ROD.
2.1.7 Two-Party Agreement Sites
Through the CERCLA investigative process, Fort Wainwright areas were evaluated to
determine whether they should be referred to another federal or state program,
recommended for NFA under CERCLA, or continued through the CERCLA process. Source
areas limited to potential petroleum contamination were deferred to the Two-Party
Agreement.
Signed by the Army and ADEC originally in 1992 and updated in 1998, the Two-Party
Agreement defined the process by which the Army agrees to investigate and clean up
petroleum-contaminated areas in accordance with Alaska State regulations. These areas
generally are associated with USTs that have leaked or surface spills of petroleum products
such as lubricating oils and grease, heating fuels, and motor fuels. For example, tanks near
six of the Motor Pools have been transferred to the Two-Party Agreement. In addition,
WQFS4, which has isolated, low-level petroleum contamination, will be addressed under
the Two-Party Agreement.
The Two-Party Agreement is part of the FFA for Fort Wainwright, and decisions for cleanup
within the Two-Parry Agreement are part of this OU5 ROD. The Two-Party Agreement
presents the petroleum cleanup strategy and documents all known historical petroleum
sources on Fort Wainwright and their current cleanup status. It also verifies the Army's
commitment to adequately address petroleum sites in a manner consistent with state
regulation.
Costs associated with sites deferred to the Two-Parry Agreement are not a component of
this ROD. These sites are not discussed further in this ROD. The Two-Party Agreement and
a figure and table identifying affected sites are provided in Appendix D.
2.2 Enforcement Activities
Fort Wainwright was placed on the National Priorities List (NPL) of CERCLA in 1990
because a number of sites associated with known or suspected releases of hazardous
chemicals were identified on the post. As a result, environmental assessment and
remediation activities at Fort Wainwright are being performed to comply with CERCLA, as
amended by the Superfund Amendments and Reauthorization Act (SARA) of 1986 and
subsequent amendments.
These activities also are being performed to comply with a 1992 Federal Facility Agreement
(FFA) among the U.S. Environmental Protection Agency (EPA), the Department of the
Army, and the ADEC. The FFA identifies the authorities and responsibilities of these
parties, integrates CERCLA requirements with pertinent aspects of other federal and state
remedial programs, and defines schedules and general requirements for investigation
and/or remediation at areas suspected of being historical sources of hazardous waste.
An additional goal of the FFA was to integrate the Army's CERCLA response obligations
and Resource Conservation and Recovery Act (RCRA) corrective action obligations. The
ANC/TRM501.DOC/991030010 FINAL OUS ROD 15
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StTE HSTOflY AND ENFORCSMENT ACTlVmES
FFA enabled the Army to obtain a RCRA Part B permit for its interim status facilities. This
permit was issued during spring 1992. Remedial actions implemented under this ROD will
be protective of human health and the environment and will meet the substantive
requirements of the National Oil and Hazardous Substances Pollution Contingency Plan
(NCP).
The FFA divided Fort Wainwright into five OUs and required a risk assessment "to evaluate
any ecological or human health cumulative risk effects which may become evident from the
aggregate of the source areas at Fort Wainwright not addressed in prior OU remedial
investigation/feasibility studies."
The Army and ADEC signed a Two-Party Agreement in 1992 to define the process by which
the Army agrees to investigate and dean up petroleum-contaminated areas. These areas
generally are associated with USTs that have leaked or surface spills of petroleum products
such as lubricating oils/grease, heating fuels, and motor fuels. The areas identified and
placed in the Two-Party Agreement are identified in Appendix D.
2.3 Highlights of Community Participation
The public was encouraged to participate in the selection of the remedies for OUS during a
public comment period from June 17 to July 17, 1998. The Proposed Plan for Remedial Action,
Operable Unit 5, Fort Wainwright, Alaska, presents combination s of options considered by the
Army, ADEC, and EPA to address contamination in soil and groundwater at WQFS1,
WQFS2, WQFS3, EQFS, and Remedial Area 1A of OUS. The Proposed Plan was released to
the public on June 16, 1998, and was sent to all known interested parties, which included
approximately 150 concerned citizens.
Community relations activities conducted for Fort Wainwright, which includes OUS, began
in 1992. A community relations plan was prepared in 1993 and updated in 1997. Fact sheets
describing the environmental restoration activities at all Fort Wainwright OUs have been
distributed regularly since 1993. The Restoration Advisory Board, a group that focuses on
restoration and community relations activities, first met in 1997 and has met quarterly since
then.
The Proposed Plan summarizes cleanup alternatives for OUS. Additional materials were
placed in two information repositories: one at the Noel Wien Library in Fairbanks and the
other at the Fort Wainwright Post Library. An Administrative Record, including all items
placed in the information repositories and other documents used in the selection of the
remedial actions, was established in Building 3023 on Fort Wainwright. The public is invited
to inspect materials available in the Administrative Record and the information repositories
during business hours.
Interested citizens were invited to comment on the Proposed Plan and the remedy selection
process by mailing comments to the Fort Wainwright project manager, calling a toll-free
telephone number to record a comment, or attending and commenting at a public meeting
on June 25, 1998, in Fairbanks at the Carlson Center. The public did not provide any
comments on the Proposed Plan.
16 FINALOU5ROD ANC/TRM501.DOC/991030010
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STTEHSTORV AND ENFORCEMENT ACTIVITIES
Display advertisements in the Fairbanks Daily News-Miner, published on June 19,21, 24,
and 25,1998, also included information about the information repositories, the toll-free
telephone line, and an address for submitting written comments.
The Responsiveness Summary provides a background discussion of community
involvement activities conducted in association with OU5. This document is Appendix A of
this ROD.
This ROD presents the selected remedial actions for OU5 chosen in accordance with
CERCLA as amended by SARA and, to the extent practicable, the NCP. The decision for
OU5 is based on information and documents that are in the Administrative Record.
2.4 Scope and Role of Operable Units
As with many CERCLA sites at large installations and with many source areas, the
problems at Fort Wainwright are complex. The potential source areas were grouped into
OUs based on the amount of existing information, the similarity of potential hazardous
substance contamination, and the level of effort required to complete an RI. OUS will be the
fifth and last OU to have completed the RI/FS process and begin remedial activities. OUs 1,
2,3, and 4 have been addressed in previous RODs; only OU5 is addressed in this ROD.
OUS contains source units resulting from past fuel leaks, spills, waste storage, and other
facility activities, and groundwater under these source units. The source sites originally
were in three general areas: WQFS, EQFS, and OB/OD area. Additional CERCLA sites have
been transferred into OUS from other OUs: Remedial Area 1A (Birch Hill Underground
Storage Tanks), Motor Pool Buildings, Former EOD Range, and sites deferred to the Two-
Party Agreement.
The RI fieldwork was completed and reported with the risk assessment in the 1996 Operable
Unit 5 Remedial Investigation Report, Fort Waimvright, Alaska (three volumes). The feasibility
study (FS) was completed and reported in 1998 in Operable Unit 5 Feasibility Study, Fort
Wainwright, Alaska. A risk assessment was completed for the entire Fort Wainwright area to
supplement the individual risk assessments developed for each of the five OUs and other
designated source areas at the site. The objective of the postwide risk assessment was to
evaluate any ecological or human health cumulative risk effects that may become evident
from the aggregate of the source areas and not addressed in the previous OU RI/FSs. The RI
and FS denned potential risks posed by existing groundwater contamination and the
potential for migration if remediation does not occur. The Chena River was identified as the
area most likely to be affected by multiple source areas. As a result, the Chena River Aquatic
Assessment Program was initiated to evaluate potential impacts.
This ROD presents the selected remedial actions for OUS source areas in accordance with
CERCLA as amended by SARA and, to the extent practicable, the NCP. The decision for
OUS is based on information and documents that are in the Administrative Record.
The actions identified in this ROD are intended to significantly reduce risks to human health
and the environment associated with contamination resulting from past activities at Fort
Wainwright. The principal threats, as defined by EPA guidance, are the highly
contaminated subsurface soils, floating product layer, smear zones, and groundwater in the
ANOTRM501.DOC/991030010 FINAL OUS ROD 17
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SHE HISTORY AND ENFORCEMENT ACTIVITIES
WQFS source areas. Treatment has been selected as an element of the remedial action for
these principal threats.
18 FINAL OU5 ROD
ANC/TRM501.DOCW91030010
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SECTION 3
Summary of Source Area Characteristics
The transport pathways, hydrogeologic conditions, and nature and extent of contamination
for the WQFS, EQFS, and Remedial Area 1A source areas are summarized in the following
sections.
3.1 Transport Pathways and Hydrogeologic Conditions
This section provides a brief discussion of factors affecting the migration of contaminants
detected in soil, groundwater, sediment, and surface water at OU5.
3.1.1 Air Transport
Organic compounds detected in surface soil at OU5, especially aromatic hydrocarbons
(benzene, toluene, ethylbenzene, and xylenes [BTEX]), may volatilize and be transported by
air. Because of the significant dilution caused by the atmosphere, volatilization is expected
to be a minor transport pathway. When wind speed is high enough to suspend small
surface-soil particles (dust), site contaminants sorbed to the dust particles may be
transported off site. Because most contamination in OU5, with the exception of Remedial
Area 1A, is subsurface, the transport of airborne particulates is relatively insignificant.
3.1.2 Surf ace Water Runoff
Surface water runoff at OU5 is relatively insignificant, because the majority of precipitation
infiltrates directly into the porous soils, then returns to the atmosphere through
evapotranspiration. When surface-water runoff occurs, surface-water migration occurs as
intermittent overland flow during rainfall or snowmelt. Surface-water runoff from WQFS
and EQFS eventually drains toward the Chena River. The Chena River flows through the
northern portion of the cantonment area, then through Fairbanks before it joins the Tanana
River approximately 8 miles west-southwest of Fort Wainwright.
3.1.3 Migration in Soil to Groundwater
Solvents and petroleum hydrocarbons are the contaminants of concern (COCs) in the OU5
source area soil. At WQFS and EQFS, dissolved chlorinated solvents are present in
groundwater. No evidence of free-phase or immiscible dense free product has been found in
saturated or unsaturated soil in these areas. Concentrations do not indicate a free-product
source in the groundwater.
In general, the contaminants were released to the soil as nonaqueous-phase liquid (referred
to as free product), most of which migrated down through the soil by gravity. Some of the
hydrocarbon liquid remains held in the soil pores by capillary forces and becomes
immiscible. This condition is termed residual saturation. The concentration of petroleum (in
soil) at residual saturation is expected to be several thousand to tens of thousands of
milligrams per kilogram of soil for the sand and gravel at the OU5 sites. Free product at or
ANC/TRM50i.DOC/991030010 FINAL OU5 ROD 19
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JUMMARYOF SOURCE AREA CHARACTERISTICS
below residual saturation will not migrate downward through the soil by gravity, but may
be transported down by percolating water, both as immiscible globules and in solution.
Sources of percolating water at the OU5 sites include infiltrating snowmelt and rainfall. The
extent of contaminant infiltration into subsurface soil depends on the ability of specific
contaminants to adsorb to or react with subsurface soil particles. The majority of
groundwater'contamination in OU5 is a result of subsurface releases such as pipeline breaks
and leaking tanks.
•
The principles governing downward migration of floating product through the unsaturated
zone also apply to heavier-than-water free product, such as trichloroethene (TCE). Upon
reaching the water table, the heavier-than-water, or dense, nonaqueous-phase liquids
(referred to as dense free product) displaces the water and continues downward until
reaching residual saturation and becoming immobile. Because dense free product does not
float on the water table, significant lateral spreading does not occur. As a result, the
contaminated soil "footprint" is relatively small and therefore more difficult to detect than
floating product.
Lighter-than-water nonaqueous-phase liquids (referred to as floating product), such as
gasoline or diesel, have a specific gravity of approximately 0.7 to 0.85 and, therefore, float on
water. Accumulations of floating-product petroleum hydrocarbons are sometimes referred
to as free-phase petroleum hydrocarbons or free product. The term floating product is used
in this ROD.
When sufficient floating product reaches the water table, it tends to depress the water table.
These contaminants tend to spread horizontally on the surface of the water table from the
force of the buoyancy of the water and from the force of additional contaminants migrating
from above. The contaminants at the water-table surface fluctuate vertically as the water
table fluctuates, and as the water table drops, contaminants enter soil pores that were
formerly filled with water. During high water, some floating product becomes trapped
below the water table in the soil pores. The groundwater zone containing floating product
between the low and high water levels is sometimes referred to as the "smear zone." At
WQFS and EQFS, the smear zone is located in the interval between approximately 12 and
18 feet below ground surface. Floating product continues to move with the water table until
it is transformed into residual saturation or is degraded.
Both free-phase and residual saturation are sources for contaminants dissolving into
groundwater.
3.1.4 Groundwater Migration
The aquifer beneath the OU5 area consists of glacially derived sands and gravels (Chena
alluvium) that have been transported and reworked by the Tanana and Chena rivers. The
alluvium has been described as a heterogeneous mixture of coarser and finer soil lenses of
relatively small size, a description that is consistent with logs of borings installed in the area.
The aquifer ranges from a few feet thick at the base of Birch Hill to at least 300 feet thick
under the cantonment, and may reach thicknesses of up to 700 feet in the Tanana River
valley. The aquifer is considered unconfined in permafrost-free areas, such as OU5. The
horizontal hydraulic conductivity is estimated to be 125 to 400 feet per day. The vertical
hydraulic conductivity is estimated to be one-twentieth of the horizontal hydraulic
20 FINAL OU5 ROD
ANC/TRM501.DOC/991030010
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SUMMARVOF SOURCE AREA CHAR4CTEWS7KS
conductivity. The water table generally is encountered within 10 to 15 feet below ground
surface and flows generally west-northwest on the south side of the Chena River. The
groundwater flow direction and gradient are influenced strongly by the Chena River.
Dissolved contaminants migrate in groundwater by advection and dispersion. Groundwater
is expected to move with an average linear velocity of 1.0 to 1.5 feet per day in the OU5 area.
Contaminants have been carried with the groundwater flow approximately 2,000 feet
downgradient of the main source area within WQFS. The shape and location of the plume
suggest that downward gradients have carried contaminants into, beneath, and north of the
Chena River. Dissolved contaminants (benzene and total aromatic hydrocarbon [TAH])
were detected at concentrations greater than the federal maximum contaminant level (MCL)
and Alaska Water Quality Standards at depths up to 70 feet below ground surface.
Contaminants also have been detected at concentrations greater than MCLs at groundwater
sampling locations north of the Chena River.
3.1.5 Groundwater and Chena River Interaction
Shallow groundwater flows into or out of the riverbed and riverbanks depending on the
elevation of the water in the river relative to the groundwater table. Seasonally, the
discharge of the river fluctuates from a high during late May or early June snowmelt to a
low in late April or early May, which is late winter and presnowmelt. The river stage also
may rise in response to summer rainfall. The groundwater table generally rises and falls in
response to these river fluctuations, but is less affected with increasing distance from the
river.
High-flow events in the Chena River produce transient changes in the groundwater flow
regime, temporarily reversing the groundwater flow direction and gradient. The duration of
these transient events is typically several days. These transient events generally occur
during two periods: the spring snowmelt and late-summer precipitation, which results in
peak flows in the Chena River.
Groundwater contaminants enter the Chena River and potentially affect aquatic receptors
and downgradient groundwater users, including residents of the City of Fairbanks.
Modeling simulations indicate that during most of the year groundwater flows in a
northwesterly direction and intersects (recharges) the Chena River. Flow lines that originate
at depths of 60 feet or more are thought to flow beneath the river. The flow lines have no
hydraulic connection to the river (at that point). Simulations indicate that water flowing
beneath the river has an upward gradient within 1,000 feet north of the river and tends to
rise toward the surface and turn in a westerly direction to join the river before the next
meander. Transient high-water events in the Chena River (such as during breakup) tend to
reverse the flow into and under the river. They also cause temporary flow downward and
away from the river at all depths. The flow reversal propagates to distances of
approximately 1,500 feet from the river.
Groundwater flow transports dissolved contaminants to the Chena River. The groundwater
is quickly diluted by the river flow; therefore, only low-level contaminants have been
detected in the Chena River. U.S. Geological Survey records indicate that the average
discharge for the Chena River at Fairbanks in a 42-year recording period was 1,371 cubic
feet per second.
ANCyrHM501.DOC/99103001Q FINAL OU5 ROD 21
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SUMMARY Of SOURCe AREA CHARACTERISTICS
3.1.6 Sediment Transport
Less volatile fractions of transported groundwater contaminants are found in sediments in
the OU5 reach of the Chena River. Contaminated sediment particles are transported with
river flow act as hydraulic forces on the riverbed and riverbanks. The particles produce
mass transfer and reshape the river channel. The rate of contaminated sediment transport is
affected by many factors, including geologic characteristics of the sediment, hydrologic
cycles, geometric characteristics of the river, and hydraulic characteristics such as depth,
slope, and velocity.
3.1.7 Potential Transport Pathways and Receptors
At OU5, chemicals in soil, sediment, and groundwater are potentially available to human
and ecological receptors. Transport pathways considered for an evaluation of human health
risks are ingestion, dermal contact, and inhalation of particulates for soil; and ingestion,
dermal contact, and inhalation of VOCs (through air) for groundwater contaminants. The
potential current and future receptors assessed are facility workers, construction workers,
and military and nonmilitary residents. The pathways considered for ecological receptors
are ingestion of soil, sediment, and surface water; ingestion of terrestrial and aquatic plants;
and exposure to sediment and surface water. The risk assessments for the source areas are
summarized in Section 4.
3.2 Nature and Extent of Contamination
Investigations at WQFS before the OU5 RI included surface and subsurface soil samples,
shallow borings, and monitoring wells. These investigations are identified in the 1996 OU5
RI report. The 1994 North Airfield groundwater investigation (documented in the 1995
North Airfield Groundwater Investigation, Fort Wainwright Alaska, report) identified several
groundwater plumes. Two free-product plumes are in WQFS. The larger plume extends
about 4-1/2 acres and encompasses more of the area where fuel pumps, dispenser islands,
and storage tanks were located. The smaller free-product plume extends about 600 feet
southwest of Building 1599 and coincides with a bermed area around a possible fuel
containment structure. A benzene plume covers about 25 acres, at least 25 feet thick. A
plume of 1,2-dichloroethane (1,2-DCA) extends from north of Front Street to the Chena
River, overlapping the free-product and benzene plumes. Estimated depth of the plume is
20 feet. Dissolved diesel-range organics (DRO) and gasoline-range organics (GRO) also were
detected in WQFS, but the extents were not defined.
Soil sampling at Building 1599 showed fuel contaminants extending from the ground
surface to the groundwater table near fuel facilities. The data suggested that the
concentrations increased with depth between zero and 15 feet and were typically greatest
near the groundwater table, where hydrocarbons had accumulated. Sampling also indicated
the presence of pesticides in soils at concentrations below screening levels. However,
because of high levels of hydrocarbons found in soil samples, uncertainty exists about the
laboratory data for exact concentrations of pesticides. In the 1997 Record of Decision for
Operable Unit 1, Fort Wainwright, Fairbanks, Alaska, remediation of petroleum-contaminated
soils at Building 1599 was deferred to the Two-Party Agreement between the Army and
ADEC. The groundwater under the site, however, is addressed in OU5.
22 F1NALOUSROO ANC/TRM501.DOC/991030010
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SUMMARY OF SOURCE ABEA CHARACTERISTICS
Data from pre-RI investigations indicated that groundwater contaminant plumes were not
discrete; they were commingled. To better address the complexity of these commingled
plumes in a cost-effective and comprehensive manner, the project managers combined
source area groundwater investigations into the Quartermaster areas identified in the RI.
Contaminants detected in 1994 at the 55-gallon drum site along the Chena River included
petroleum hydrocarbons and benzene. Although the contents did not impart a sheen to the
river, a surface water sample collected within 10 feet of the drums contained benzene at
1.3 micrograms per liter (ng/L). Other organic contaminants were detected in the surface
water at other locations. Sediment sampling at the river bank and sampling of river water
during the OU5 RI showed contaminants above potential applicable or relevant and
appropriate requirements (ARARs).
The COCs for OU5 are identified and assessed for potential risk in the November 1996
Operable Unit 5 Remedial Investigation Report, Fort Wainwright, Alaska; the November 1997
Operable Unit 5 Feasibility Study, Fort Wainwright, Alaska; and the April 1995 Feasibility Study,
Operable Unit 3, Fort Wainwright, Alaska (for Remedial Area 1 A).
3.2.1 WQFS Nature and Extent of Contamination
The COCs at WQFSl, WQFS2, and WQFS3 are discussed below and summarized in Table 1.
Contaminants identified at WQFS include chlorinated VOCs and petroleum hydrocarbons
in groundwater and petroleum hydrocarbons and PAHs in soil. The approximate extent
TABLE1
Summary of Soil and Groundwater Sample Results for Contaminants of Concem-WQFS
Medium Contaminant
Soil DRQ
GRO
Benzene
Ethylbenzene
Toluene
Xylenes
Groundwater Benzene
Toluene
1,2-DCA
TCE
TAH
TAqH
No. of Detections/
No. of Samples
118/184
43/184
9/184
21/184
24/184
30/184
16/19
16/19
9/19
2/19
14/19
12/19
Range of Detected
Concentrations
4 - 54,000
5 - 5,300
0.002 - 3.7
0.082 - 31
0.002 - 91
0.003-220
0.3-960
0.1-2,500
0.3 - 41
36 - 42
13-6,230
19-6.773
Notes:
1. Soil concentrations are in milligrams per kilogram. Groundwater concentrations (remediation goal and
detected) are in micrograms per liter.
TAqH = Total aqueous hydrocarbon
ANC/TRM501.DOC/991030010 FINAL OU5 ROD 23
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SUMMARY OF SOURCE AREA CHARACTERISTICS
of soil and groundwater contamination is shown in Figure 3. Contaminated soil volume
estimates are presented in Table 2.
vff.fi Extent of Soil Contamination
Extent of Groundwater Contamination
Figure 3. Extent of Groundwater and Soil Contamination at OU5
TABLE2
Contaminated Soil Volume Estimates
Source Area
WQFS
Total volume of affected
EQFS
Remedial Area 1A
Subarea
WQFS1
WQFS2
WQFS3
soil at WQFS
Contaminants
DRO. GRO. BTEX
DRO, GRO, BTEX
DRO, GRO
DRO, GRO, BTEX
lead
Estimated Volume of
Contaminated Soil
(cubic yards)
139,000
8,300
3,300
150.600
73,100
1,200
Notes:
1. Estimated volumes are based on analytical data, field observations, and professional judgment.
2. Volumes in place do not include expansion, which would occur with excavation.
3. Volumes do not include uncontaminated overburden soil or uncontaminated soil that would be removed for
sloping or benching excavation walls.
T
2* FINAL OU5 ROD
ANC/TRM501 .DOC/991030010
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SUMMARY OF SOURCE AREA CHARACTERISTICS
3.2.1.1 Soil
WQFS1 Soil. Soil COCs at WQFS1 include DRO, GRO, and BTEX. Vehicle maintenance
activities at former Building 1599 and spills and leaks from former fuel storage and handling
facilities are the primary sources of petroleum hydrocarbon contaminants. The estimated
volumes of contaminated soil are shown in Table 2.
WQFS2 Soil. At WQFS2 (adjacent to the Chena River), soil COCs are DRO, GRO, toluene,
ethylbenzene, and xylenes. The 8-inch fuel pipeline that parallels Gaffney Road and the
former ASTs are the suspected sources of petroleum hydrocarbons. The estimated volumes
of contaminated soil are shown in Table 2.
WQFS3 Soil. Soil COCs at WQFS3 (adjacent to the Chena River) are DRO and GRO. The
suspected sources of petroleum hydrocarbons in subsurface soil are a 6-inch wood-stave
pipe, through which diesel and gasoline were channeled during fuel releases in 1971, and
possible drum storage or road-maintenance activities. The estimated volumes of
contaminated soil are shown in Table 2.
WQFS4 Soil. Soil at the WQFS4 is being addressed under the Two Party Agreement between
the Army and the ADEC (see Appendix D.)
3.2.1.2 Groundwater
The extent of contamination in groundwater at the WQFS is not discussed by subarea
because groundwater plumes from various sources combine across the subarea boundaries
(Figure 3). The contaminants benzene, toluene, 1,2-DCA, TCE, TAH, and total aqueous
hydrocarbon (TAqH) were detected in groundwater samples at concentrations exceeding
state or federal standards, or both. These contaminants and the ranges and frequencies of
detection's are summarized in Table 1. Additionally, pesticides below action levels were
detected in groundwater near Building 1599. Although these concentrations do not pose an
unacceptable risk, detection levels were elevated because of high levels of petroleum
products.
Groundwater contaminants extend deeper than 70 feet below ground surface (more than
60 feet below the water table). The aerial extent for groundwater contamination in the EQFS
and WQFS is approximately 43 acres. Groundwater contaminants from the WQFS are
released into the Chena River. The primary sources of contaminants in groundwater at
WQFS are from surface disposals of solvents, spills and leaks, and other past disposal
practices at Building 1599. Solvents and petroleum hydrocarbons in soil and free product in
the smear zone are secondary sources of contamination in groundwater at WQFS.
3.2.1.3 Free Product
Two distinct plumes of free product (mostly jet fuel and diesel fuel) floating on
groundwater have been encountered in WQFS:
1. A plume south of Gaffney Road that encompasses most of the area where fuel pumps,
dispenser islands, and fuel storage tanks were located
2. A plume between Gaffney Road and the former retaining structure on the Chena River
ANOTRM501.DOC/991030010 FINAL OU5 ROD 25
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SUMMARY OF SOURCE AREA CHARACTERISTICS
The observed thickness and extent of free product plumes vary with seasonal fluctuations in
groundwater levels. Thicknesses range from a sheen to approximately 1 foot; the areal
extent in the WQFS is approximately 5 acres. These plumes are generally within the
boundaries of the groundwater contamination plume shown in Figure 3.
Samples of free product were collected from probes within the largest plume and were
analyzed for fuel identification and quantisation, kinematic viscosity, and specific gravity.
The project laboratory identified the product from each probe as kerosene or gasoline. The
quality assurance (QA) laboratory identified the product as diesel fuel No. 2 or JP-4 jet fuel.
Historical records indicate that both diesel and gasoline were stored at the site.
3.2.2 EQFS Nature and Extent of Contamination
Figure 3 shows the approximate extent of soil and groundwater contamination in EQFS.
Contaminated soil volume estimates are presented in Table 2. Before fieldwork for the OU5
RI was conducted, other investigations of the sources at EQFS were performed from 1989 to
1994. These studies collected soil and groundwater samples to identify contamination at
source areas within EQFS. They are summarized in the RI 'report. The 1994 North Airfield
groundwater investigation was the most extensive of these previous investigations. Results
of this investigation showed groundwater plumes of the following:
• Free product (about 1 /4 acre)
• Benzene (about 1-1/2 acres)
• 1,1,1-trichloroethane (1,1,1-TCA) (extending about 300 feet, but no plume size provided)
• TCE and cis-l,2-dichloroethene (cis-1, 2-DCE) (a degradation product of TCE, both
plumes extending about 600 feet but no plume sizes provided)
• DRO (plume not defined)
• GRO (plume not defined)
3.2.2.1 Soil
Soil COCs at EQFS include DRO, GRO, and xylenes (Table 3). The suspected source of
petroleum hydrocarbon contamination in the area south of Building 1565 is past and current
fueling operations (storage tanks, fuel bladders, and fuel tanker trucks). Soil contamination
in this area has extended to the groundwater table. Near Building 1575, GRO is found in a
localized area of smear zone soil. The presumed source is a leak in the abandoned 6-inch
underground fuel pipeline. Petroleum contamination also was found south of Taxiway 18.
Fuel-dispensing equipment from a former fuel station near Building 1070 and past road-
maintenance activities are other suspected sources of petroleum hydrocarbon contamination
in surface soil. The suspected sources of petroleum hydrocarbon contamination in
subsurface soil near Building 1070 are former USTs and the abandoned 8-inch and 6-inch
fuel pipelines. The source of subsurface, contamination north of Apple Street near the Chena
River is unknown, but may be related to fuel releases channeled through a wood-stave pipe
protruding from the bank of the Chena River.
26 FINAL OU5 ROD ANC/TRM501.DOC/991030010
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SUMMAflY OF SOURCE AREA CHMACTEKSTtCS
3.2.2.2 Groundwater
Groundwater COCs at EQFS that exceed state and federal MCLs are TCE, 1,1,1-TCA,
1,2-ethylene dibromide, bis(2-choroethyl)ether, TAH, TAqH, and benzene (Table 3). Two
distinct groundwater plumes have been identified in EQFS: one slightly upgradient and one
downgradient of Building 1565. The suspected sources are as follows:
• For petroleum hydrocarbon compounds in the groundwater plume south and east of
Building 1565, an abandoned fuel pipeline near the airfield
• For petroleum contaminants near Building 1575, an abandoned 6-inch fuel pipeline
• For benzene, spills and leaks from the former fueling station southeast of Building 1070
• For 1,1,1-TCA 1,2-ethylene dibromide, and TCE, undocumented spills
1,1,1-TCA was not detected at concentrations above the MCL of 200 ug/L in the wells
sampled during the OU5 RI. It was detected in one monitoring well at a concentration of
190 ug/L. In previous investigations and in a 1997 groundwater study, 1,1,1-TCA in
groundwater had been identified at concentrations above the MCL. The highest
concentration detected was 1,100 ug/L in 1989. Therefore, 1,1,1-TCA has been carried
forward as a COC. The source of the 1,1,1-TCA may be an undocumented spill or spills west
of Building 1565 and between buildings 1576 and 1578. The 1,2-DCA is believed to be
associated with degradation of the 1,1,1-TCA plume. The decreasing concentration of
1,1,1-TCA and the presence of 1,2-DCA suggest that the plume may be attenuating through
natural processes (anaerobic biotransformation).
TABLES
Summary of Soil and Groundwater Sample Results for Contaminants of Concem-EQFS
Medium Contaminant
Soil DRO
GRO
Xylenes
Groundwater Benzene
TCE
1,1,1-TCA
1 ,2-ethylene dibromide
bis(2-chloroethyl)ether
TAH
TAqH
No. of Detections/
No. of Samples
64/114
21/114
11/114
12/25
9/25
NA
5/25
1/25
8/25
7/25
Range of Detected
Concentrations
4-10,600
4 - 5,900
5-72
0.1 -18
0.4 - 60
1,100 (max)
0.02 - 0.46
0.5
10-160.6
18.6-175.6
Notes:
1. Soil concentrations are in milligrams per kilogram. Groundwater concentrations (remediation goal and
detected) are in micrograms per liter.
2. ADEC soil matrix concentrations will be used as guidance for in situ treatment of soils.
NA = Not available
ANOTRM501.DOC/991030010 FINAL OU5 ROD 27
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SUMMARY OF SOUSCg AREA CHARACTERISTICS
3,2.2,3 Free Product
A plume of free product was encountered in EQFS south of Building 1060 and east of
Building 1070 during previous investigations. The free-product plume covered up to 1 acre,
encompassing the area where the former fuel station, dispensers, and 25,000-gallon gasoline
tank were located. During the OU5 RI, measurements in wells and probes in this area did
not indicate that free product was present. To confirm the absence of free product, several
probes were purged with a peristaltic pump to allow direct observation of the groundwater.
The presence of a thin layer of product was noted after examining water purged from south
of Building 1060 near Gaffney Road.
A sample of free product was collected for fuel identification. Analytical results from the
project laboratory identify the product as kerosene; the QA laboratory identified the product
as mineral spirits. On the basis of site history, the product is likely to be weathered gasoline.
3.2.3 Chena River
Free product flows into the Chena River from the WQFS through bank seeps. Numerous
surface stains are visible along river banks of the WQFS. Additional contamination is
transported into the river from contaminated groundwater.
Results of the OU5 RI indicate that average concentrations of the following chemicals in
sediment collected from the Chena River at WQFS or EQFS areas exceed preliminary
ecological screening criteria: 2-methylnaphthalene, fluorene, naphthalene, phenanthrene,
^'-dichlorodiphenyldichloroethane (ODD), 4,4'-dichlorodiphenyldichloroethene (DDE),
4,4'-dichlorodiphenyltrichloroethane (DDT), and lead. Maximum concentrations of a few
additional chemicals such as dieldrin also exceeded the screening criteria. For some
chemicals, criteria were not available. With the exception of petroleum compounds, PAHs,
and dieldrin, the distribution of contaminants does not suggest a localized source.
Exceedances of screening levels indicate a potential for impacts to the Chena River
ecosystem.
To determine whether actual impacts have occurred, assess their significance, and measure
changes over time, the Chena River Aquatic Assessment Program was initiated. The
assessment includes collecting water, sediment, and detritus (organic leaf litter) samples
during the spring and fall and analyzing them for COCs and water chemistry. A second
year of study was completed, with results to be reported during the first quarter of 1999.
Benthic macroinvertebrates such as insects and larvae also will be collected and analyzed
through toxicological studies and bioassays. Additional details on the completed aquatic
assessment and ongoing studies are provided in the FS.
3.2.4 Remedial Area 1 A
Lead contamination was detected at various sampling locations within Remedial Area 1 A.
Sixteen borings were drilled and 47 surface soil samples were collected. Total lead was
detected in all surface soil samples with concentrations ranging from 8.3 milligrams per
kilogram (mg/kg) to 7,840 mg/kg. Nine samples had total lead concentrations above
1,000 mg/kg, the lead screening level for industrial land uses.
Surface soil lead contamination may be the result of several historical tank maintenance
activities. These activities included tank bolt removal and replacement, cleaning sludge
28 FINAL OU5 ROD ANOTRM501.DOC/991030010
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SUMMARY OP SOURCE AREA CHARACtEMCTCS
from tank bottoms, and tank painting and stripping. Historically, bolts removed from the
tanks during routine maintenance were cleaned with a solvent to remove red lead pipe
dope. The solvent, which contained lead from the threaded bolt pipe dope, was spread on
the ground in the areas surrounding the tanks. Because these tanks were built as bolted
(rather than welded) tanks, a very large number of bolts are present on each tank. Sludge
removed from the bottoms of the fuel tanks was buried or spread in the areas surrounding
the tanks and may have contributed to lead contamination in these areas. Paint from
stripping operations also may have contributed lead to surface area soU. In addition,
releases of lead-containing fuels may have contributed to the elevated lead concentrations
near the ASTs.
Lead contamination of surface soil is most significant directly adjacent to each tank, with
lead levels decreasing as lateral distance increases from each AST. In addition, lead
concentrations in subsurface soils decrease to background levels at depths of 1 to 2 feet A
1996 field investigation further identified five surface soil samples in Remedial Area 1A
with leachable lead concentrations that exceed the EPA toxicity characteristic leaching
procedure (TCLP) criterion of 5 milligrams per liter (mg/L) for hazardous waste.
An evaluation indicated that lead was the only inorganic analyte above screening levels. All
VOCs and semivolatile organic compounds (SVOCs) initially identified as chemicals of
potential concern (COPCs) were retained, except acetone and bis(2-ethylhexyl)phthalate.
These analytes were excluded because they are common laboratory contaminants and were
detected frequently in blanks.
AN
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SUMMARY OF SOURCE AREA CHARACTERISTICS
30 FINAL OUS ROD
ANC/TRM501.DOC/991030010
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SECTION 4
Summary of Site Risks
Baseline human health and ecological risk assessments were performed for WQFS, EQFS,
and Remedial Area 1A to determine the need to take action at the source areas and to
indicate the exposure pathways that need to be addressed by remedial action. A more
detailed presentation of the baseline risk assessments for EQFS and WQFS are contained in
the 1996 Operable Unit 5 Remedial Investigation Report, Fort Wainwright, Alaska. The baseline
risk assessment for Remedial Area 1A is contained in the 1994 Operable Unit 3 Remedial
Investigation Report, Fort Wainzvright, Alaska. The baseline risk assessments determine
potential risks to humans and the environment in the absence of remedial action. Both
current- and potential future-exposure scenarios were considered for WQFS, EQFS, and
Remedial Area 1A. A conceptual site model was developed that identified possible
exposure pathways between site chemicals and different human populations. The current
population at the source areas is facility workers; potential future populations that were
considered include facility workers, construction workers, and military and nonmilitary
residents.
In addition to the risk assessments for WQFS, EQFS, and Remedial Area 1 A, described
above, postwide human health and ecological risk assessments were performed to evaluate
any human health or ecological cumulative risk effects that may become evident from the
aggregate of source areas at Fort Wainwright not addressed in individual OU RIs and FSs.
These assessments were documented in the 1997 Postwide Risk Assessment, Fort Wainwright,
Alaska. The postwide risk assessment was designed to consider unique exposure and risk
scenarios that transcend the boundaries of individual source areas and OUs, supplementing
the human health and ecological risk assessments for the five OUs and designated source
areas at Fort Wainwright.
4.1 Human Health Risk Assessment
The human health risk assessment was performed by using information on toxicity of
contaminants and assumptions about the extent to which people may be exposed to them.
Although future residential scenarios were completed for OUS source areas, they were
determined to not be appropriate for soils because industrial use is the reasonably
anticipated future use based on the Fort Wainwright master plan and historical use of both
areas. It was determined that future residential risks identified in the baseline human health
risk assessment are applicable to groundwater because an exposure pathway for domestic
water users currently exists. The NCP requires that groundwater be returned to its
beneficial uses whenever practicable. At WQFS and EQFS, the beneficial use is domestic
water supply.
4.1.1 Identification of Contaminants of Concern (Screening Analysis)
Analytical sampling data were screened in a two-step process to select a list of site-related
COCs that potentially contribute to human health risks at the source areas. First, the
maximum concentrations of contaminants detected in onsite soil and water during the RIs
ANC/rRM502.DOC/991030011 FINAL OUS ROD 31
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SUMMARY OF SITE RISKS
were compared to health-based screening levels for soil and drinking water developed by
EPA Region 3 (April 1,1998) and Region 10 (Supplemental Risk Assessment Guidance, 1991).
These standards reflect residential exposure assumptions of 1 x 10-* and 1 x 10-7 risks
associated with groundwater and soil, respectively, or a hazard quotient of 0.1 for all media.
Chemicals detected at concentrations below the risk-based screening concentrations were
eliminated from the source-area risk assessments. If risk-based screening concentrations
were not available, maximum groundwater concentrations were compared to Safe Drinking
Water Act MCLs.
Second, inorganic chemicals were compared to naturally occurring background levels. If
maximum concentrations of inorganic chemicals were determined to be below established
background levels, they were eliminated from further evaluation. Table 4 presents the
COCs identified in the soil and groundwater at the WQES, EQFS, and Remedial Area 1 A.
4.1.2 Exposure Assessment
The exposure assessment estimates the type and magnitude of exposures to the COCs at the
source areas. It considers the current and potential future uses of the site, characterizes the
potentially exposed populations, identifies the important exposure pathways, and
quantifies the intake of each COC from each medium for each population at risk. The
current population at WQFS, EQFS, and Remedial Area 1A is facility workers. Potential
TABLE4
Contaminants of Concern for Human Health Risk Assessment
Contaminated Medium in Source Area
Analyte WQFS EQFS Remedial Area 1A
Benzene Soil, GW GW
bis(2-chloroe»hy!)ether -- GW
DRO . Soil Soil
1,2-Ethylene dibromide - GW
1,2-DichIoroethane GW
Ethylbenzene Soil
GRO Soil Soil
Lead - - Soil
TAH GW GW
TaqH GW GW
Toluene Soil, GW -- -
Trichloroethene GW GW
Xylenes Soil Soil
Notes:
-- = Not identified as a COC in environmental media at this source area
GW = Groundwater
32 FINAL OUS ROD ANOTRM502.DOC/991030011
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SUMMARY OF SITE RISKS
future populations that were considered include facility workers, construction workers, and
military and nonmilitary residents.
Potential exposures were evaluated for both average-exposure and reasonable-maximum-
exposure scenarios. The average-exposure scenario was estimated by using average-
exposure concentrations (such as average soil or groundwater concentrations) and exposure
variables that represent central values or best estimates of exposure for an individual with
normal activity patterns. The reasonable-maximum-exposure scenario has been estimated
by using EPA risk assessment guidance. The intent of evaluating the reasonable-maximum
exposure is to estimate a conservative-exposure scenario that is still within the range of
possible exposures. Because of the uncertainty surrounding any estimate of exposure
concentration, the EPA recommends that the 95 percent upper confidence limit of the
arithmetic mean be used for the exposure point concentration of COCs in calculating risks
for reasonable-maximum exposure. If the 95 percent upper confidence limit exceeded the
maximum detected concentration, the maximum detected concentration was used as the
concentration for evaluation of the risk of reasonable maximum exposure.
Exposure frequency for soil exposure was modified to reflect the fact that the ground at Fort
Wainwright is snow covered and/or frozen for at least 6 months per year. The snow cover
reduces by 6 months per year the time that any receptor could be in contact with the soil.
The appropriate changes were made for the receptors (facility worker, construction worker,
and military and nonmilitary residents) and pathways (ingestion and dermal contact) that
were used to evaluate exposure to chemicals in the soil. This assumption was determined .
by the EPA and ADEC to be representative of conditions at Fort Wainwright.
In the postwide human health risk assessment, exposure assumptions for reasonable-
maximum exposure and average-case exposure scenarios were developed for a hunter,
fisherman, and recreational swimmer assumed to be exposed to postwide contaminants.
These exposure scenarios assumed exposures anywhere on the installation and that no
cleanup action had occurred. Exposure pathways evaluated included incidental ingestion of
surface soil, ingestion of moose and fish meat, and incidental ingestion of surface water.
The exposure point concentrations used to estimate potential risk in the postwide human
health risk assessment were the maximum detected concentration for the reasonable-
maximum-exposure scenario and the arithmetic mean concentration of COCs for the
average-exposure scenario.
Data about the concentration of contaminants of concern in the media of concern at the
source area (the exposure point concentrations) were combined with information about the
projected behaviors and characteristics of the people who potentially may be exposed to
these media (exposure parameters) to estimate exposure. The calculated value of the
exposure point concentration is intended to represent the distribution of the chemical
within a specific medium. Separate exposure point concentrations have been calculated for
each medium for WQFS, EQFS, and Remedial Area 1 A.
Analytical data for soil at the source areas were divided into separate databases
corresponding to surface and subsurface soil. This approach allowed a separate evaluation
of potential exposures to different populations. Surface soil is defined as all surficial
samples and samples collected to a depth of 0.5 foot below ground surface. Subsurface soil
is defined as all soil samples from the surface to a maximum depth of 10 feet below ground
surface. It is unlikely that excavation or construction activities would disturb soil deeper
ANC/THM502.DOC/991030011 RNALOU5ROO 33
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SUMMARY OF SITE RISKS
than 10 feet below ground surface because of the presence of permafrost throughout the
Fort Wainwright area. Inclusion of the surface soil profile in the subsurface soil database is
appropriate because exposure to subsurface soil through intrusive activities also will
include exposure to surface soil.
4.1.2.1 EPA Region 10 Guidance on the Use of Nondetect Data Points
EPA Region 10 recommends that a value of one-half the detection limit be used for
nondetected concentrations in soil and groundwater to calculate the exposure point
concentration if the detection limit is equal to or less than the maximum detected
concentration. For nondetected concentrations with a detection limit greater than the
maximum detected concentration, but less than twice the maximum detected concentration,
the nondetected data point would be replaced with a surrogate concentration equal to one-
half the maximum detected concentration. For nondetected concentrations with a detection
limit equal to or greater than twice the maximum detected concentration, the nondetected
data point would be replaced with a surrogate concentration equal to the maximum
detected concentration. This conservative approach is intended to avoid underestimating
exposure point concentrations for chemicals that are potentially present but are masked by
high detection limits. However, elevated detection limits were generally not an issue for the
data sets for WQFS, EQFS, and Remedial Area 1A.
4.1.2.2 Exposure Parameters
The parameters used to calculate average-exposure and reasonable-maximum-exposure
were obtained from the EPA Region 10 human health risk assessment guidance
(Supplemental Risk Assessment Guidance for Superfund, 1991). The parameters include body
weight, age, contact rate, frequency of exposure, and exposure duration. Default exposure
factors were modified to reflect climatological and other factors specific to Fort Wainwright.
Site-specific exposure assumptions for soil contact, including soil ingestion, dermal contact,
and dust inhalation, were modified based on the site being snow-covered for half the year.
4.1.2.3 Exposure Point Concentrations
Exposure point concentrations were calculated for the surface soil, subsurface soil, and
groundwater for WQFS, EQFS, and Remedial Area 1A. Before exposure point
concentrations were calculated, the analytical data for the source areas were evaluated to
assess whether any areas of significantly elevated concentrations were present.'No
discernible areas were identified. The exposure point concentrations for average exposure
and reasonable maximum exposure are represented by the arithmetic mean and the 95
percent upper confidence limit, respectively, of the analytical data for each of the detected
compounds retained as COCs. These concentrations are presented in the baseline risk
assessments for WQFS and EQFS (Operable Unit 5 Remedial Investigation Report, Fort
Wainwright, Alaska) and for Remedial Area 1A (Operable Unit 3 Remedial Investigation Report,
Fort Wainwright, Alaska).
Because of the large number of nondetected concentrations in the analytical data for the
COCs, the arithmetic mean concentration and the 95 percent upper confidence limit are
generally the same value. In addition, the maximum detected concentrations for the COCs
are less than two orders of magnitude greater than the arithmetic mean concentration. This
finding indicates that, in general, there was not a wide variability in the distribution of
34 RNAUOU5ROD ANC/rRM502.DOC/991030011
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SUMMARY OF SITS RISKS
chemicals in the different media. Consequently, the exposure point concentrations for
average exposure and reasonable maximum exposure are the same value for most COCs.
4.1.3 Toxicity Assessment
Human health toxicity factors were identified for the COCs. Toxicity factors were identified
for both carcinogens (slope factors) and noncarcinogens (reference doses [RfDs]). Only
chronic toxicity criteria were used in the human health risk assessment. Oral toxicity factors
were used to evaluate both oral and dermal exposures. Inhalation toxicity factors were used
to evaluate inhalation exposure to volatile chemicals. Dermal absorption factors and
permeability coefficients recommended by the EPA were used to assess risks from dermal
contact with chemicals in soil and groundwater.
The toxicity factors were drawn from the Integrated Risk Information System or, if no
Integrated Risk Information System values were available, from the Health Effects
Assessment Summary Tables. For chemicals that do not have toxicity values available, other
criteria, such as state and federal MCLs, were used to,assess potential hazards or to
determine action levels.
4.1.4 Risk Characterization
The purpose of the risk characterization is to integrate the results of the exposure and
toxicity assessments to estimate risk to humans from exposure to site contaminants. Risks
were calculated for carcinogenic (cancer-causing) and noncarcinogenic (toxic) effects for
both the average-exposure and reasonable-maximum-exposure scenarios (see Section 4.1.2).
To estimate cancer risk, the slope factor is multiplied by the exposure expected for that
chemical to provide an estimate of the excess lifetime cancer risk. This estimate is the
incremental probability of an individual developing cancer over a lifetime as a result of
exposure to cancer-causing chemicals at a source area. The EPA considers excess lifetime
cancer risks between 1 in 1 million (1 x 1O6) and 1 in 10,000 (1 x 10-*) to be within the
generally acceptable range; risks greater than 1 in 10,000 usually suggest the need to take
action at a site.
In defining effects from noncancer-causing contaminants, the EPA considers acceptable
exposure levels to be those that do not adversely affect humans over their expected lifetime,
with a built-in margin of safety. Potential concern for noncarcinogenic effects of a single
contaminant in a single medium is expressed as a hazard quotient, which is the ratio of the
estimated exposure from a site contaminant to the RfD of that contaminant. If the hazard
quotient is less than 1, adverse noncancer health effects are unlikely to occur. Hazard
quotients for individual COCs are summed to yield a hazard index for a site. If the hazard
index exceeds 1, the individual contributions (hazard quotients) to the sum should be
evaluated for possible systemic toxic effects.
Cancer risks and noncancer health effects were characterized for each human population of
interest at WQFS, EQFS, and Remedial Area 1A. Risk summaries for WQFS and EQFS are
presented in Tables 5 and 6, respectively, and are discussed below.
ANOTRM502 DOC/991030011 . FINAL OUS ROD 35
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SUMMARY OF SITE RISKS
TABLES
Summary of Total Cancer Risks and Noncancer Hazard Indices for Potentially Exposed Populations at WQFS
Receptor/Pathway
Facility Worker
Surface soil ingestion
Total
Construction Worker
Surface soil ingestion
Total
Construction Worker
Subsurface soil ingestion
Total
Future Nonmllitary Resident
Surface soil ingestion
Total
Future Nonmllitary Resident
Subsurface soil ingestion
Total
Future Nonmllitary Resident
Groundwater ingestion
Groundwater inhalation of VOCs
Groundwater dermal contact
Total
Future Military Resident
Groundwater ingestion
Groundwater inhalation of VOCs
Groundwater dermal contact
Total
Cancer
Average
5.2E-09
5.2E-09
1.0E-09
1.0E-09
1.1E-09
1.1E-09
1.3E-07
1.3E-07
1.3E-07
1.3E-07
7.4E-06
7.4E-06
1.5E-06
1.6E-05
1.7E-06
1.6E-06
3.4E-07
3.6E-06
Risks
RME
7.0E-08
7.0E-08
6.5E-08
6.5E-08
6.5E-08 .
6.5E-08
6.4E-07
6.4E-07
6.4E-07
6.4E-07
1.2E-04
1.2E-04
8.9E-06
2.5E-04
2.1E-05
2.0E-05
1.5E-06
4.2E-05
Noncancer Hazard Indices
Average RME
NA NA
NA NA
NA MA
NA MA
NA NA
7.0E-02 3.9E-01
1.1E+00 5.6E+00
4.3E-02 8.8E-02
1.2E+00 6.1E+00
7.0E-02 3.9EE-01
1.1E+00 5.6E+00
4.3E-02 8.8E-02
1.2E+00 6.1E+00
Notes:
All average and RME risks are based on the mean and 95 percent upper confidence limit concentrations,
respectively.
NA = Not applicable; no noncancer chemicals were selected as COCs
RME = Reasonable maximum exposure
36 FINAL OUS ROD
ANC/TRM502.DOO991030011
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TABLES
Summary of Total Cancer Risks and Noncancer Hazard Indices for Potentially Exposed Populations at EQFS
Receptor/Pathway
Facility Worker
Surface soil dermal
Surface soil ingestion
Total
Construction Worker
Surface soil dermal
Surface soil ingestion
Total
Construction Worker
Subsurface soil dermal
Subsurface soil ingestion
Total
Future Nonmilitary Resident
Surface soil dermal
Surface soil ingestion
Total
Future Nonmilitary Resident
Subsurface soil dermal
Subsurface soil ingestion
Total
Future Nonmilitary Resident
Groundwater ingestion
Groundwater inhalation of VOCs
Groundwater dermal contact
Total
Future Military Resident
Groundwater ingestion
Groundwater inhalation of VOCs
Groundwater dermal contact
Total
Cancer
Average
2.5E-1 1
9.9E-09
9.9E-09
3.2E-12
1.9E-09
1.9E-09
1.4E-11
2.4E-09
2.4E-09
1.1E-11
2.4E-07
2.4E-07
4.8E-11
2.8E-07
2.BE-07
1.1E-05
1.0E-06
1.3E-07
1.2E-05
2.4E-06
2.2E-07
2.9E-08
2.6E-06
Risks
RME
8.8E-10
1.7E-07
8.BE-07
1.1E-10
1.5E-07
1.5E-07
6.7E-10
1.7E-07
1.7E-07
9.4E-10
1.5E-06
1.SE-06
5.8E-09
1.7E-06
1.7E-06
1.7E-04
•K2E-05
8.0E-07
1.9E-04
2.9E-05
2.0E-06
1.3E-07
3.1E-05
Noncancer
Hazard Indices
Average
6.3E-07
2.1E-07
8.4E-07
4.0E-07
2.1E-07
6.2E-07
1.9E-06
9.7E-07
2.8E-06
2.9E-07
1.7E-06
2.0E-06
1.3E-06
7.7E-06
9.1E-06
1.2E-02
2.6E-02
1.9E-04
3.8E-02
1.2E-02
2.6E-02
1.9E-04
3.8E-02
RME
8.8E-06
1.2E-06
1.0E-05
5.4E-06
5.4E-06
1.1E-05
3.3E-05
3.3E-05
6.7E-05
7.8E-06
9.0E-06
1.7E-05
4.8E-05
5.4E-05
1.0E-04
5.9E-02
1.3E-01
3.4E-04 •
1.9E-01
5.9E-02
1.3E-01
3.4E-04
1.9E-01
ANCTRM502.DOC/991030011
FINAL OU5 ROD 37
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SUMMARY OF SHE RISKS
TABLES
Summary of Total Cancer Risks and Noncancer Hazard Indices for Potentially Exposed Populations at EQFS
Noncancer
Cancer Risks Hazard Indices
Receptor/Pathway Average RME Average RME
Future Military Resident
Surface soil dermal
Total
Future Military Resident
Subsurface soil dermal
Total
2.3E-12
2.3E-12
1.1E-11
1.1E-11
1.6E-10
1.6E-10
9.6E-10
9.6E-10
2.9E-07
2.9E-07
1.3E-06
1.3E-06
7.8E-OiB
7.8E-OS
4.8E-05
4.8E-05
Notes:
All average and RME risks are based on the mean and 95 percent upper confidence limit concentrations,
respectively.
RME = Reasonable maximum exposure
VOCs = Volatile organic compounds
4.1.4.1 WQFSArea
The total cancer risks Delated to surface and subsurface soil exposure at WQFS for the
facility worker, construction worker, and the future resident are all less than 1 x 10"6. The
total cancer risks for reasonable maximum exposure related to groundwater use are
2.5 x 1CH for a future nonmilitary resident and 4.3 x 10~5 for a future military resident. Risk
is greater to future nonmilitary residents because they are assumed to have the EPA 30-year
average exposure while future military residents are assumed to have a 5-year average
exposure. Most of this risk (88 percent) is contributed by benzene, which was consistently
detected in groundwater at concentrations exceeding the MCL. Most of the remaining risk
is contributed by 1,2-DCA.
The noncancer hazard index of reasonable maximum exposure for residential groundwater
use for both future military and nonmilitary resident is 6.1. Although this hazard index
exceeds the EPA benchmark of 1.0, most of this value is contributed by benzene, which was
evaluated by using an interim, unverified inhalation RfD for benzene. If benzene is omitted
from the noncancer evaluation, the total hazard index is approximately 1.0.
4.1.4.2 EQFS Area
The total cancer risks of reasonable maximum exposure related to surface and subsurface
soil exposure at EQFS for both the facility worker and the construction worker were less
than 1 x 10"6. The total cancer risks of reasonable maximum exposure related to surface and
subsurface soil exposure for the future nonmilitary resident are less than 2 x 10"6 and are at
the lower end of the EPA acceptable risk range of 1 x 10"6 to 1 x 10'4. The total cancer risks
of reasonable maximum exposure related to surface and subsurface soil exposure for a
future military resident are less than 1 x 10"9. The total cancer risks of reasonable maximum
exposure related to groundwater use are 1.9 x 10"4 for future nonmilitary resident and
3.1 x 10"5 for a future military resident. Risk is greater to future nonmilitary residents
38 FINAL 005 ROD ANC/TRMS02.00Q991030011
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SUMMARY OF SITE RISKS
because they are assumed to have the EPA 30-year average exposure while future military
residents are assumed to have a 5-year average exposure.
1,2-ethylene dibromide contamination only occurs in ground water and does not appear to
be widespread. At the worst, 1,2-ethylene dibromide is very isolated in occurrence (as
reported in the final human health risk assessment for OU5). The calculation that 1,2-
ethylene dibromide is the major contributor to risks related to ground water use of 1.9 x 1(H
for a future nonmilitary resident and 3.1 x 10~5 for a future military resident must be
weighed against the facts that 1,2-ethylene dibromide was detected in only 4 of 22 samples
and only 2 of the detections were above the MCL.
Total noncancer risks for all populations at EQFS were below a hazard index of 1.0.
4.1.4.3 Remedial Area 1A
Estimates of cancer risks and hazard indices for potential excess lifetime exposure
developed for the human health risk assessment are within or below the regulatory
benchmarks defined under current land-use conditions. Estimates of cancer risk below
1 x 10"6 and noncancer risk below a hazard index of 1.0 reflect the absence of complete
exposure pathways by which potential receptors could contact site-related contaminants
and the relatively low concentrations of COCs detected in soils and groundwater. Potential
cancer and noncancer risks in excess of regulatory guidelines were associated only with
potential future domestic use of onsite groundwater.
Lead contamination was detected at various surface soil sampling locations in Remedial
Area 1A. The EPA does not currently recommend numerical estimates for cancer risk from
lead because human evidence of lead as a carcinogen is inadequate. Toxic effects of lead are
correlated with blood-lead levels rather than exposure levels or daily intake. Lead is a
poison that causes toxic effects in virtually every system in the body, and no lowest effect
level of exposure or daily intake has been identified. In Remedial Area 1 A, levels of lead
exist in excess of EPA guidance for industrial cleanup levels for soil; however, a risk or
hazard index cannot be calculated for lead exposure. Additionally, lead levels detected
exceed the State of Alaska regulation of 1,000 mg/kg for total lead in Title 18, Chapter 75, of
the Alaska Administrative Code (AAC).
Lead was not included in the quantitative risk estimates because it has no EPA-approved
RfD or slope factor. Instead, lead concentrations in Remedial Area 1A soils were assessed by
comparing the exposure point concentrations in soil with the concentrations generated by
using the default assumptions of the uptake/biokinetic model. However, the
uptake/biokinetic model does not address lead exposure to older children or adults.
Therefore, the risks associated with exposures of adult residents and workers and of
adolescent site visitors could not be evaluated quantitatively.
4.1.4.4 Postwide Human Health Risk Assessment
The postwide human health risk assessment determined excess lifetime cancer risks for the
hunter, based on moose ingestion, to be 5 x 10~* for the reasonable-maximum-exposure
scenario and 3 x 10"6 for the average-exposure scenario. Noncancer hazard indices, based on
calculated values for moose meat ingestion, were 5.2 for the reasonable-maximum-exposure
scenario and 0.2 for the average-exposure scenario. The primary contributors to the excess
cancer risks were dioxins/furans, PAHs, DDT, dieldrin, and arsenic. Dioxins and furans
AN(yrRM502.DOO991030011 RNALOU5ROD 39
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SUMMARY OF SITE RISKS
were responsible for approximately 78 percent of the moose ingestion risk for the hunter.
Noncancer hazard indices were primarily from inorganic chemicals, with mercury
(43 percent) and zinc (30 percent) posing the majority of the reasonable-maximum-exposure
risk. For further discussion, see Section 4.1.5, Uncertainly Analysis.
The excess-lifetime cancer risks associated with fish ingestion were 1 x 10"* for the
reasonable-maximum-exposure scenario and 4 x 10*5 for the average-exposure scenario.
Noncancer hazard indices based on fish ingestion were 1.6 for the reasonable-maximum-
exposure scenario and 0.8 for the average-exposure scenario. The primary contributors to
the excess cancer risks for the reasonable-maximum-exposure scenario were beryllium.
(56 percent), dieldrin (32 percent), and DDT (11 percent). Because dieldrin was detected
only once in the Chena River surface water and DDT and beryllium only twice, the
uncertainty associated with these risk estimates is very high. These chemicals are indicated
as COCs for the Chena River in Table 7.
Surface-water-ingestion risks for the recreational swimmer in the postwide human health
risk assessment ranged from 2 x 1(H to 3 x 10~7 for the reasonable-maximum-exposure and
average-exposure scenarios, respectively. Surface-water-ingestion risks were primarily from
arsenic and beryllium, which were detected at concentrations consistent with background
concentrations. These chemicals are indicated as COCs for the Chena River in Table 7.
4.1.5 Uncertainty Analysis
It is important to identify the primary limitations and areas of uncertainty in a risk
assessment, so that risk management decisions may be informed and accurate. Many
assumptions used in a human health risk assessment are conservative, to avoid
underestimating the risk for anyone potentially, exposed at the site. Areas of uncertainty for
the WQFS, EQFS, Remedial Area 1 A, and postwide human health risk assessments include
the sampling and analysis program, the exposure assessment, the toxicity assessment, and
the risk characterization, which are discussed below.
4.1.5.1 Sampling and Analysis
The human health risk assessment is based on soil and groundwater data specific to each
source area. In general, the large numbers of samples collected are considered to be
adequate for evaluation of current site conditions. Although natural attenuation and human
.'ctivities may result in a decrease in concentrations over time, it was conservatively
assumed that chemical concentrations would be constant in the future.
4.1.5.2 Exposure Assessment
Performance of a risk assessment requires numerous assumptions about site populations,
exposure pathways, and exposure assumptions. A major uncertainty inherent in risk
assessments for military bases relates to the duration of exposure. This human health risk
assessment uses the EPA recommended default value of 30 years for residential exposure;
however, most military assignments are for much shorter periods of time, often for only 1 to
3 years. A military resident was evaluated with an exposure duration of 5 years.
For the purposes of completing baseline risk calculations, a future residential scenario was
assumed for the WQFS, EQFS, and Remedial Area 1A, with use of site groundwater for
domestic purposes. Groundwater is the only source of potable water used at Fort
<0 FINAL OU5 ROD ANC/TRMS02.DOCO91030011
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TABLE?
Contaminants of Concern for the Chena River Based on Results of the PostwkJe Risk Assessment
Analyte
Ecological Risk Assessment
Sediment Segment •
ABODE
Surface Water Segment *
AGO
Human Health Risk Assessment
Surface Water
Fish Ingestion Surface Water Ingestlon
Volatile Organic Compounds
2-Butanoneb'c-d
Acetoneb'd X
Methylene chlorided
n-Butylbenzeneb
o-Propylbenzeneb
p-lsopropyltolueneb
X
X
X
X
X
X
Semlvolatile Organic Compounds
1,2,4-Trichloroben2eneb
1,2,4-Trimethylbenzeneb
1,3,5-Trimethylbenzeneb
2-Methylnaphthalene
Acenaphthene
bis(2-ethylhexyl)phthalateb'd
Butylbenzyl phthalateb'd
Di-n-butyl phthalateb'd
Diethylphthalateb'c'd
Fluorene
Naphthalene
Phenanthrene
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
ANC/TRM502.DOC/M1030011
FINAL OU5 ROD
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TABLE?
Contaminants of Concern for the Chena River Based on Results of the Poslwitfe Risk Assessment
Ecological Risk Assessment
Sediment Segment •
Analyte ABODE
Surface Water Segment '
A C D
Human Health Risk Assessment
Surface Water
Rsh Ingestlon Surface Water Ingestlon
Organochlorlne Pesticides and Polychlorlnated Blphenyls
4,4'-DDD
4,4'-DDE
4,4'-DDT
Aroclor 1260
beta-Hexachlorocyclohexane
Dieldrin
gamma-
Hexachlorocyclohexane
X
X
X
X
X
X
Dioxins/Furans
2,3,7,8-Trichlorodibenzo-p-
dioxin toxicity equivalent
Metals
Arsenic
Barium0
Beryllium8
lronc
Lead
Manganese0
Nickel9
Sodium0-e
X
X
X
X
X
C^MSO? DOC/991030011
FINAL OU5 ROD
-------
TABLE?
Contaminants of Concern for the Chena River Based on Results of the Postwide Risk Assessment
Analyte
Ecological Risk Assessment
Sediment Segment '
ABODE
Surface Water Segment *
A C D
Human Health Risk Assessment
Surface Water
Ran Ingestion Surface Water Ingestion
Five ri
eamens - ave .
^ risk assessments The boundaries of Segments A-E were based on spatial distribution of sample locafons,
which were associated with various potential contaminant sources.
b Indicated as a COC because ecological sediment criteria are not available.
c Indicated as a COC because ecological surface-water criteria are not available.
• Maximum postwide concentration is consistent with Chena River background concentrations based on August 1995 and January 1997 background sampling
results (Postwide Risk Assessment, Fort Wainwright, Alaska, 1997).
Notes: .
x - COC based on postwide risk assessment results
Ldiment~screening criteria were based on guidance from the National Oceanic and Atmospheric Administration, Ontano Ministry of Environment and Energy,
New York Department of Environmental Conservation, and Washington State Department of Ecology.
FINAL OU5 ROD
ANOTRM502.00C/991030011
-------
SUMMARY OF StTCBtSKS
Wainwright and throughout the Fairbanks area. Ninety-five percent of the Fort Wainwright
potable water is supplied through a single distribution system fed by two large-capacity
wells near the Power Plant (building 3559). The City of Fairbanks uses the same aquifer and
has four supply wells of the municipal utility 1 mile downgradient of post boundaries on
the banks of the Chena River.
Chemical concentrations in soil and groundwater were assumed to remain constant over
time. No consideration was given to biotic or abiotic processes that would be expected to
reduce chemical concentrations in these media through time.
The postwide human health risk assessment included the following significant
uncertainties, which could overestimate risk:
• The hunter is assumed to ingest meat from moose that use a home range limited to the
Fort Wainwright cantonment area and that are in contact with the maximum detected
concentration of all chemicals at all times. Although moose range across very large
areas, the cantonment area offers some of the least desirable habitat for moose on Fort
Wainwright. Additionally, hunting is not allowed in the main cantonment area. A large
percentage of the calculated risks to the hunter are from background concentrations of
the risk drivers.
• The fisherman's risk drivers are dieldrin, which was only detected once in Chena River
water, and DDT and beryllium, which were only detected twice in Chena River water.
In addition, this pathway requires partition modeling based on water concentrations to
obtain fish tissue concentrations.
• The swimmer's risk drivers are arsenic and beryllium, which were detected at
concentrations consistent with background concentrations.
4.1.5.3 Toxicity Assessment
The toxicity factors used in performance of human health risk assessments also are
associated with a high degree of uncertainty. Several specific uncertainties in toxicity factors
pertain to the risk assessments for OU5. Surrogate toxicity factors were used to evaluate the
potential risk associated with structurally similar chemicals that lack EPA-verified toxicity
factors. It was not possible to quantitatively assess potential risks from gasoline, diesel, and
other petroleum hydrocarbons, although constituents such as benzene and toluene, which
may or may not be attributable to petroleum, were quantitatively evaluated.
Because toxicity factors have not been developed for the dermal exposure route, oral
toxicity factors were used to evaluate the dermal toxicity of chemicals. As a result, all risk
estimates associated with the dermal exposure pathway are conservatively overestimated
and should be viewed with caution.
4.1.5.4 Risk Characterization
The risk characterization combines exposure and toxicity assessment information to
estimate potential risk for a site. Therefore, the uncertainties associated with the exposure
and toxicity assessments are combined in the risk characterization. Concentrations of
chemicals detected in the different media were assumed to remain constant for the entire
duration of exposure, not considering environmental degradation from physical, chemical,
44
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SUUUAftYOFSfTEFUSKS
or biological actions. Risks from different chemicals were assumed to be additive, which
may not always be correct. Risks from multiple chemicals may be independent (through
different mechanisms of action) or additive (through the same mechanism of action).
Potential risks from other exposure pathways or from chemicals other than the COCs were
not considered.
4.2 Ecological Risk Assessment
An ecological risk assessment was performed to assess whether chemicals associated with
site activities at WQFS, EQFS, or Remedial Area 1A may adversely affect local populations
of ecological receptors. The ecological risk assessment was conducted in three steps-
problem formulation, analysis, and risk characterization. The assessment was consistent
with the EPA framework document for ecological risk assessment and used chemical data
compiled during RI activities.
4.2.1 Ecological Problem Formulation
Ecological habitat surveys were performed at each source area, and the site-specific
information obtained during these surveys was used to identify relevant receptors. A
screening assessment was conducted as part of the problem formulation step to identify
COPCs at each source area based on a chemical data review and a toxicity screening
assessment.
Conceptual models were developed for the source areas based on the COPCs that were
identified. A conceptual model is defined as a written or pictorial representation of an .
environmental system and the biological, physical, and chemical processes that determine
the transport of contaminants from sources through environmental media to receptors
within the system. Potential exposures to various ecological receptors and trophic levels
were considered in the development of the conceptual model. Potential terrestrial receptors
include plants, birds, amphibians, soil invertebrates, and burrowing and non-burrowing
mammals. Potential aquatic receptors include plants, birds, amphibians, benthic
invertebrates, fish, and mammals. Measurement and assessment end points were selected
based on the characteristics of the identified stressors (COPCs), the ecosystem and its
components that may be at risk (indicator species), and the expected or observed ecological
effects associated with the stressors.
Indicator species were selected to focus the ecological risk assessment on a subset of
potential receptors that have adequate exposure and toxicity information in the scientific
literature. Terrestrial and aquatic species with small home ranges were evaluated to assess
potential risks for specific source areas. Predatory species with larger home ranges were
quantitatively evaluated in the postwide ecological risk assessment. The relative
contribution of WQFS, EQFS, and Remedial Area 1A source areas to the exposure of these
receptors was assessed as part of the postwide ecological risk assessment.
At WQFS, EQFS, and Remedial Area 1 A, chemicals in soil, sediment, and surface water are
potentially available to ecological receptors. The COPCs identified for ecological receptors
are shown in Table 8. Mammalian indicator species selected for WQFS and EQFS include
the meadow vole (exposure pathways include ingestion of plants and ingestion of soil) and
the muskrat (exposure pathways include ingestion of aquatic plants, ingestion of sediment,
ANC/TRM5020OO991030011 FINAL OU5 ROD
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SUMMARY OF SHE BISKS
TABLES
Contaminants of Potential Concern for the OU5 Ecological Risk Assessment
Soil
Sediment
Contaminant
WQFS
EQFS
WQFS
EQFS
Surface Water
WQFS
EQFS
Volatile Organic Compounds
1,2,3-Trichlorobenzene
1,2,4-Trimethylbenzene
1,3,5-Trimethylbenzene
2-Butanone
Acetone
Benzene
Isopropylbenzene
n-Butyl benzene
X
X
X
X
X
X
X
X
X
X
Semlvolatlle Organic Compounds
2-Methylnaphthalene
BenzyJ butyl phthalate
bis{2-ethyihexyl)phthalate
DI-n-butyl phthalate
Diethyl phthalate
Fluorene
Naphthalene
Phenathrene
X
X
X
X
X
X
X
X
X
X
X
X
X
PesticIdes/PCBs
4.4'-DDD
4,4'-DDE
4,4'-DDT
X
X
X
Inorganics
Arsenic
Cadmium
X
X
Lead
Mercury
X
X
Notes: " ~~ ~
ODD as Oichlorodiphenyldichloroethane
DDE = Dichlorodiphenyldichloroethene
DDT = Dichforodiphenyltrichloroethane
X = Indicates that this chemical was selected as a potential COC for the designated source area and media
FINAL OUS ROD
ANC/TRMS02.DOC/9910300T 1
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SUMMARY OF SfTE RISKS
and ingestion of surface water). Other aquatic indicators selected for WQFS and EQFS
include benthic invertebrates (exposure pathways include exposure to sediment and surface
water). The postwide ecological risk assessment identified the red fox as an indicator
species to represent terrestrial receptors because it is omnivorous and, therefore, is more
likely to bioaccumulate chemicals than herbivores whose diets consist of plants.
Bioaccumulation factors for animals generally are higher than plant uptake factors for the
same chemicals.
4.2.2 Ecological Risk Analysis
The analysis phase consists of two main components: (1) characterization of exposure, and
(2) characterization of ecological effects. Conservative assumptions were used in estimating
potential exposure and effects to the selected indicator species.
Species-specific exposure parameters and equations for complete exposure pathways were
developed for mammalian indicator species. The average daily doses calculated for
individual pathways were summed to obtain chemical-specific average daily doses, which
were used to estimate exposure. Potential exposure pathways for the meadow vole,
including plant ingestion and soil ingestion, were evaluated for WQFS and EQFS.
Exposures to sediment and surface water were not evaluated because meadow voles inhabit
upland areas. The average chemical concentrations from the top zero to 0.5 foot of soil were
used for the quantitative assessment of risk to the meadow vole.
Potential exposure pathways for the muskrat, including plant ingestion, sediment ingestion,
and surface water ingestion, were evaluated separately for WQFS and EQFS and for the
combined WQFS and EQFS areas. Exposure to soil was not evaluated because muskrats are
primarily present in aquatic habitats. The chemical concentrations of soil, sediment, and
surface water used in the analysis and risk characterization were the average concentrations
over a given source area. The sediment data and the surface water data also were averaged
over WQFS and EQFS to assess potential impacts to muskrats throughout the segment of
the Chena River adjacent to both of these source areas.
Chemical exposure to benthic invertebrates was evaluated separately for WQFS and EQFS
by comparing average chemical concentrations in sediment and surface water for each
source area to applicable sediment and surface-water quality criteria.
Ecological effects were characterized by using toxicity reference values identified in the
scientific literature. Where available, published benchmark values intended to protect biota
were used as toxicity reference values to qualitatively assess the potential adverse effects to
benthic invertebrates from chemicals in sediment and surface water. Toxicity reference
values used in the quantitative assessment of potential adverse effects to the meadow vole
and muskrat were developed from published toxicity values based on toxicological studies
on laboratory animals. Toxicity reference values used in the ecological risk assessments for
WQFS, EQFS, and Remedial Area 1A included no observed adverse effect levels, lowest
observed adverse effect levels, and taxa-specific levels from the scientific literature.
The postwide ecological risk assessment was developed and organized according to EPA
and Army guidance. Terrestrial receptors evaluated in the postwide ecological risk
assessment included the red fox and the northern goshawk. Aquatic receptors evaluated
include benthic invertebrates and salmonids.
ANC/TRM502.DOC#91030011 RNA10U5ROO 47
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SUMMARY Of SITE RISKS
The postwide ecological risk assessment distinguished two home range groups for the red
fox. Group 1 included source areas north of the Chena River (including Remedial Area 1A).
Group 2 included a larger set of source areas (including WQFS and EQFS) south of the
Chena River. Because the red fox is omnivorous, individual hazard indices were
determined for small-mammal ingestion, bird ingestion, soil ingestion, and plant ingestion.
Toxicity threshold limit values for the red fox were derived by using rat and mouse toxitiry
data, with uncertainty factors to account for different toxicological end points and different
taxonomic relationships between the test organism and indicator species.
4.2.3 Ecological Risk Characterization
Risk characterization consists of two steps: (1) risk estimation and (2) risk description. Risks
were characterized separately for selected indicator species at WQFS, EQFS, and Remedial
Area 1 A. In addition, combined risk from sediment and surface water from both WQFS and
EQFS was estimated for the muskrat. Risk estimation involves integrating the exposure and
toxicity information, calculating hazard indices, and summarizing the uncertainties
identified in the assessment. Sites and media with hazard indices of 1.0 or below were
assumed to pose no significant risk to ecological receptors. For sites with hazard indices
greater than 1.0, conclusions were made about the potential ecological significance of these
risks.
Determination of hazard indices for the meadow vole, muskrat, and benthic invertebrates is
discussed in the OU5 FS for Fort Wainwright.
4.2.3.1 WQFS Area
The total hazard index estimated for the meadow vole based on the average chemical
concentrations in soil at WQFS is less than 0.01, well below the EPA level of concern
(hazard index of 1.0). On the basis of the estimated hazard index, the meadow vole and
other populations of terrestrial receptors associated with WQFS are not expected to be
affected.
A total hazard index of 1.9 was estimated for the muskrat based on the average chemical
concentrations in sediment and surface water collected from the Chena River adjacent to
WQFS. Cadmium and PAHs are the primary contributors to the overall risk. Although
potential adverse effects to individuals are indicated by the total hazard index that slightly
exceeds 1.0, the potential for adverse effects at the population level is not considered
significant. Given the nature of uncertainties in developing toxicity benchmarks (based on
extrapolations of information from laboratory studies of mice and rats) and the use of
conservative exposure parameters (assuming continuous contact with contaminated
media), a hazard index of 1.9 for the muskrat is unlikely to be significant at the population •
level.
Average concentrations of PAHs and pesticides detected in sediment collected from the
Chena River exceed sediment benchmarks, indicating potential adverse effects to benthic
invertebrates. Such benchmarks include promulgated values, such as ambient water quality
criteria for chemicals in water, as well as nonpromulgated criteria. Average concentrations
of phthalates, arsenic, cadmium, lead, and mercury detected in surface water exceed Alaska
Water Quality Standards for the protection of freshwater, aquatic organisms. These results
48 FINAL 005 ROD ANC/TRM502.DOO991030011
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SUMMARY OF SITE RISKS
indicate the potential for adverse effects to aquatic organisms in the segment of the Chena
River adjacent to WQFS.
4.2.3.2 EQFS Area
The hazard index estimated for the meadow vole based on the average chemical
concentrations in soil at EQFS is 0.01, well below the EPA level of concern (hazard index of
1.0). Acetone is the primary contributor to the overall risk. On the basis of the estimated
hazard indices, the meadow vole and populations of terrestrial receptors at EQFS are not
expected to be affected.
The hazard index estimated for the muskrat based on the average chemical concentrations
in sediment and surface water from the Chena River adjacent to EQFS is 2.5. Although
potential adverse effects to individuals are indicated by the total hazard index that exceeds
1.0, the potential for adverse effects at the population level are not considered to be
significant.
Comparison of sediment COCs to sediment benchmarks did indicate the potential for
adverse impacts to occur to aquatic organisms adjacent to EQFS. The aquatic risk was
further evaluated in the postwide ecological risk assessment.
4.2.3.3 WQFS and EQFS Areas
The hazard index estimate for the muskrat based on the average chemical concentrations in
sediment and surface water above the segment of the Chena River adjacent to both WQFS
and EQFS areas is 3.1. Arsenic, lead, and cadmium contribute the greatest overall risk.
Concentrations of arsenic, lead, and cadmium in sediment are statistically above
background, although the results of many analyses were below background. Given the
nature of uncertainties in developing toxicity benchmarks and the use of conservative
exposure parameters, a hazard index of 3.1 for the muskrat is unlikely to be significant at
the population level.
4.2.3.4 Remedial Area 1A
Potential risks from exposure to lead and petroleum hydrocarbons exist for all terrestrial
receptors at Remedial Area 1 A. However, the source area does not provide suitable habitat
for any species because of the presence of existing facilities and human disturbance in the
area. Potential receptors would be expected to avoid Remedial Area 1A and preferentially
inhabit appropriate habitat with less disturbance. Habitat outside the source areas has not
been affected. Therefore, Remedial Area 1A would be expected to constitute only a portion
of the range of ecological receptors and a significant portion of their diet would be obtained
from outside the source areas.
4.2.3.5 Postwide Ecological Risk Assessment
The postwide ecological risk assessment addressed potential risks posed by contaminants
that accumulate in body tissue and predicted potential risks exceeding the EPA acceptable
ecological hazard index of 1.0. However, the potential for adverse effects to populations is
not considered to be significant because of unsuitable habitat in the areas considered and
uncertainty in risk estimates resulting from necessary conservative assumptions. Ecological
risks to land-based receptors were evaluated by examining the feeding habits of small
mammals and birds. Hazard indices for different ingestion pathways range from 1.8 to 225
ANC/TRMS02.DOC/991030011 FINAL OU5 ROD 49
-------
SUMMAnYOFSJTE RISKS
for
for Ae red fox and 0 01 to 1.3 for the northern goshawk. Dioxins and furans are the primary
contributors to nsk for the northern goshawk and the red fox on the south side of the Chena
River On the north side of the Chena River, lead from Remedial Area 1A is the primary
contributor for risk to the red fox, with a hazard index of 225. Dioxins and furans are
consistently present at levels below screening criteria throughout Fort Wainwright and are
not attributable to a specific source. Dioxins are likely attributable to historical aerial
pesticide applications and routine historical combustion products from the power plant.
^MeratAr ^m^iT* Sampl6S W6re C°UeCted from ** Chena K™ as a component
of both the 0135 RI and the postwide risk assessment. For evaluation purposes, the Chena
Kiver was divided into five river segments (as presented in Figure 1). A number of
contaminants exceeded surface water and sediment criteria considered protective of aquatic
hfe. These mdude DDT, dioxins, dieldrin, and PAHs. Sediment samples from Segment of
the Chena River, adjacent to the OU5 sources areas, had the greatest potential to affect
aquatic resources. The Chena River Aquatic Assessment Program will evaluate the portion
of the Chena River next to OU5 to determine actual impacts and contaminant loading
entering the river through time. The aquatic assessment includes invertebrate and chemical
^rl:^^**™^ 3nd SUtfaCe Water akmS ** river- ™d -i* considered an action
under CERCLA. The study is currently under way. Monitoring and evaluation of risk will
be completed on an agreed-upon schedule, and could result in remedial actions if
unacceptable risks are found to exist to aquatic organisms of the Chena River that cannot be
reduced through existing remedial actions.
4.3 Risk Assessment Conclusions
The risk to human or ecological receptors at WQFS, EQFS, and Remedial Area 1A has been
summarized in previous sections and described in detail in the OU3 and OU5 FSs and in
the postwide risk assessment.
The human health risk assessment predicts cancer risk for potential residential groundwater
use slightly m excess of the risk threshold of 1 x KH/The noncancer hazard index of
reasonable maximum exposure for residential groundwater use is less than the acceptable
value of 1.0 for all chemicals except benzene, which was evaluated with an inhalation RfD
that is interim and unverified. The ecological risk assessment predicts that individual
receptors in sediment and surface water environments may be exposed to risks exceeding
the EPA-acceptable ecological hazard index of 1.0.
The Postwide human health risk assessment predicts cancer risks in excess of the risk
threshold of 1 x 1(H and noncancer hazard indices in excess of 1.0 for the hunter and
fisherman. The postwide ecological risk assessment predicts risks in excess of the EPA
acceptable ecological hazard index of 1.0 for terrestrial and aquatic receptors.
WQFS and EQFS Areas:
Total carcinogenic risks related to surface and subsurface-soil exposure for the facility
^ the'military and "^military resident are predicted to
• Total carcinogenic risks in WQFS related to groundwater use are 2.5 x 10'* for a future
nonmilitary resident and 4.3 x 1Q-5 for a future military resident. Eighty-eight percent of
50 FINAL COS ROD
ANC/TRM502.DOG99103001 1
-------
SMUMFIY OF STTE RISKS
this risk is contributed by benzene, which was consistently detected in groundwater at
concentrations exceeding the MCL.
• Total carcinogenic risks in EQFS related to groundwater use are 1.9 x 1(H for a future
nonmilitary resident and 3.1 x lO"5 for a future military resident. The majority of that
risk is attributed to ethylene dibromide.
• The hazard index for potential noncarcinogenic health effects exceeds the EP A-
acceptable level of 1.0 only for future residential groundwater use. The hazard index in
WQFS is 6.1, mainly because of benzene.
• Exposure of terrestrial ecological receptors to chemicals in soil at WQFS and EQFS does
not present a risk above the EPA-acceptable risk level of 1.0.
• Exposure of the individual muskrat to chemicals in sediment predicts a hazard index of
3.1. However, the potential for adverse effects at the population level is not considered
significant.
• Exceedances of sediment criteria indicate a potential for adverse effects to occur to
benthic invertebrates within the segment of the Chena River adjacent to WQFS and
EQFS.
Remedial Area 1A:
• Existing contamination does not pose risks to humans in excess of regulatory guidelines
under current land-use scenarios. Currently, this site is fenced and has restricted access.
Although areas of contaminant concentrations in excess of soil screening levels exist,
associated risk estimates are low because of the absence of plausible exposure
mechanisms.
• Terrestrial ecological communities are not predicted to be affected by contamination at
Remedial Area 1 A, because of existing fencing. Although areas of concentrated
contamination might affect individuals, the overall ecological significance of these
impacts is low. Lead-contaminated surface soils present the highest potential to affect
terrestrial species.
Postwide Risk Assessment:
• The postwide human health risk assessment predicts total carcinogenic risks for the
hunter, based on moose ingestion, to be 5 x 10"4 and the noncancer hazard index to be
5.2. Total carcinogenic risks for the fisherman, based on fish ingestion, is predicted to be
1 x 10"4 and the noncancer hazard index to be 1.6. The uncertainty associated with these
risk estimates is very high.
• The postwide ecological risk assessment concluded that contaminants in sediment and
surface water in the Chena River, particularly in the river reach identified as Segment D
near WQFS, are present at concentrations that may adversely affect populations of
aquatic ecological receptors. The ongoing Chena River Aquatic Assessment Program
will assess the potential for adverse effects to benthic invertebrates within this segment
of the river during a 10-year period.
ANC/THM502.DOO9910300I1 RMALOU5ROD 51
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SUMUAHY OF SITE RISKS
• The postwide ecological risk assessment evaluated risk to terrestrial receptors from
bioaccumulative contaminants. The assessment predicts a hazard index for the northern
goshawk of 1.3 from dioxm/furans and DDT and a hazard index for the red fox in the
area south of the Chena River of 225, principally from dioxin. The uncertainty of these
risk assessments is very high because of conservative assumptions for ingestion and
bioaccumulation.
• The postwide risk assessment predicted lead at Remedial Area 1A to present a hazard
index of 62 to the red fox, contributing 99 percent of the risk in the areas north of the
Chena River. However, the potential for adverse effects to the red fox population is not
considered to be significant because of existing fencing, unsuitable habitat in the areas
considered, and uncertainty in risk estimates resulting from necessary conservative
assumptions.
The results of the OU5 RI indicated that various organic contaminants, including 1,2 DCA,
TCE, l,2rethylene dibromide, and benzene, are present in soil and groundwater at WQFS
and EQFS at concentrations exceeding established regulatory cleanup guidelines, including
MCLs for groundwater. Lead is present in Remedial Area 1A at concentrations exceeding
EPA soil screening guidelines. Remedial actions will be performed in response to
concentrations of contaminants in the soil and groundwater that exceed state and federal
standards.
52 FWLOU5ROD ANCVTRMS02.DOQM1030011
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SECTION 5
Description of Alternatives
5.1 Need for Remedial Action
Actual or threatened releases of hazardous substances from the OU5 source areas, if not
addressed by the response actions selected in this ROD, may present a threat to human
health, welfare, or the environment. Remedial action is necessary at the WQFS, EQFS, and
Remedial Area 1A source areas to protect human health and the environment, including the
Chena River.
Groundwater is the only source of potable water for Fort Wainwright. The Fort Wainwright
aquifer is unconfined, except in areas of permafrost. Remedial actions in WQFS and EQFS
and the Chena River Aquatic Assessment Program are recommended to protect
groundwater and the Chena River. Remedial action in Remedial Area 1A is recommended
to protect humans and terrestrial mammals. Contaminated soil acts as an ongoing source of
contamination to the groundwater in all source areas, except Remedial Area 1A.
5.1.1 WQFS Area
The specific reasons for conducting remedial actions at WQFS are provided below. The
primary emphasis is protection of groundwater and reduction of contamination entering
the Chena River.
• Groundwater contains concentrations of benzene, 1,2-DCA, toluene, and TCE that
exceed MCLs and TAH and TAqH exceeding Alaska Water Quality Standards.
• Soils contain BTEX and petroleum hydrocarbons that exceed ADEC cleanup guidelines
and have resulted in contaminated groundwater.
• VOCs, SVOCs, and petroleum hydrocarbons pose a potential risk to downgradient
groundwater users.
• Free product (floating product) has been found at the interface of the vadose zone and
groundwater.
The Chena River is adjacent to WQFS and downgradient from the areas of soil and
groundwater contamination. The water supply wells for the City of Fairbanks are within
the same unconfined aquifer as the contamination downgradient of WQFS. Groundwater
contamination from dissolved contaminants and free products within the source areas
enters the Chena River and has the potential to affect the downgradient water users.
5.1.2 EQFS Area
The specific reasons for conducting remedial actions at EQFS are provided below. The areas
of primary emphasis are protection of groundwater and monitoring to ensure that no
contaminant migration to the Chena River is occurring.
ANC/TRM503.D0099KW0005 FINAL OU5 ROD S3
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DESCRIPTION Of ALTERNATIVES
Groundwater contains concentrations of benzene, 1,2-ethylene dibromide, 1,1,1-TCA,
and TCE that exceed MCLs; bis(2-chloroethyl)ether that
and TAqH that exceed Alaska Water Quality Standards.
and TCE that exceed MCLs; bis(2-chloroethyl)ether that exceeds 1x10-6 risk; and TAH dlt
• Soils contain xylenes and petroleum products that exceed ADEC cleanup guidelines and
have resulted in contaminated groundwater.
• VOCs, SVOCs, and petroleum hydrocarbons pose a potential risk to downgradient
groundwater users.
• Free product (floating product) is floating on the groundwater at the interface of the
vadose zone and groundwater.
The Chena River is adjacent to EQFS and downgradient from the areas of soil and
groundwater contamination. The RI/FS indicated that past contamination reached the
Chena River; however, data indicate that this is no longer occurring.
5.1.3 Postwide Sampling at the Chena River
A postwide sampling program, the Chena River Aquatic Assessment Program, is currently
being implemented. It involves performing an aquatic assessment of the Chena River
during the spring and fall. The assessment includes collecting water, sediment, and detritus
(organic leaf litter) samples and analyzing them for COCs and water chemistry. In addition,
benthic macroinvertebrates such as insects and larvae will be collected and analyzed
through toxicological studies and bioassays.
5.1.4 Remedial Area 1A
The specific reason for conducting remedial actions at Remedial Area 1A is that lead-
contaminated soils within its boundaries present a potential hazard to ecological and future
human receptors if use of the land changes. Lead has been detected in soils at
concentrations greater than EPA Region 9 Industrial Preliminary Remedial Goals and State
of Alaska soil cleanup levels.
5.2 Remedial Action Objectives
The RAOs for the WQFS, EQFS, and Remedial Area 1A source areas are described below.
5.2.1 Soil
• Prevent the migration to groundwater of soil contaminants that could result in
groundwater contamination and exceedances of federal MCLs and nonzero maximum
contaminant level goals (MCLGs) and to groundwater that is closely hydrologically
connected to surface water (such as the Chena River) that could result in exceedances of
Alaska Water Quality Standards in surface water (EQFS and WQFS)
• Limit human health and terrestrial receptor exposure to lead-contaminated soil (RA1A)
54 FINAL OU5 ROD ANOTRM503.DOC/991040005
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DESCRIPTION OF ALTERNATIVES
5.2.2 Groundwater (WQFS and EQFS)
• Restore groundwater to its beneficial uses within a reasonable time frame. Reduce or
prevent further migration of contaminated groundwater from the source areas to the
downgradient aquifer or surface water bodies that are closely hydrologically connected
by achieving MCLs (where there are no nonzero MCLGs) and Alaska Water Quality
Standards. For groundwater that is hydrologically connected to surface water, Alaska
Water Quality Standards will apply for the following Fresh Water Uses: (1)(A) Water
Supply; (1)(B) Water Recreation; and (1)(C) Growth and Propagation of Fish, Shellfish,
Other Aquatic Life, and Wildlife.
• Ensure there is no risk to aquatic receptors through control of contaminant movement
through the groundwater into the Chena River
• Remove floating product to the extent practicable to eliminate film or sheen from
groundwater
• Prevent use of groundwater containing contaminants at levels above Safe Drinking
Water Act MCLs, nonzero MCLGs, or the following Alaska Water Quality Standards for
Fresh Water Uses: (1)(A) Water Supply; (1)(B) Water Recreation; and (1)(C) Growth and
Propagation of Fish, Shellfish, Other Aquatic Life, and Wildlife.
5.2.3 Chena River Sediment and Surface Water
• Reduce sources of contaminant releases to the Chena River
• Meet the following Alaska Water Quality Standards for Fresh Water Uses: (1)(A) Water
Supply; (1)(B) Water Recreation; and (1)(C) Growth and Propagation of Fish, Shellfish,
Other Aquatic Life, and Wildlife.
• Continue aquatic assessment
For purposes of protecting the Chena River aquatic resources, cleanup goals for
groundwater are expected to be achieved by treating groundwater before it enters the
Chena River. Chemical-specific cleanup goals for the media of the OU5 source areas are
summarized in Section 7.
5.3 Significant Applicable or Relevant and Appropriate
Requirements
A full list of ARARs is provided in Section 8. The following ARARs are the most significant
regulations that apply to the remedies selected for the OU5 source areas:
• Federal and state MCLs are relevant and appropriate for groundwater that is a potential
drinking water source (40 CFR141 and 18 AAC 80). These ARARs set the active
remediation goals for groundwater. Alaska Water Quality Standards (18 AAC 70) are
also applicable to surface water, sediment, and groundwater that is closely
hydrologically connected to surface water.
• Alaska oil pollution regulations (18 AAC 75) are applicable and require the cleanup of
oil or hazardous material releases.
ANC/TRM503.DOO991040005
FINAL OU5 BOO 55
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DESC81PT10N OF ALTERNATIVES
5.4 Description of Alternatives
Many technologies were considered for use in cleaning up the soil and groundwater in the
source areas. The most favorable options that passed the preliminary screening were
assembled into preliminary remedial alternatives addressing the RAOs established for soil
and groundwater in OU5. These alternatives were evaluated based on their effectiveness
unplementability, and relative costs. Experience gained from installing and operating '
treatment systems in four OUs previously addressed at Fort Wainwright and from
treatabihty study systems (discussed in Section 2) also were considered as part of this
evaluation. The preliminary remedial alternatives are listed in Table 9 and described below.
With the exception of the no-action alternative, all alternatives discussed below include
institutional controls and monitoring.
^tSS"* mV6r u-qUatiC Assessment Program is an ongoing program. The information
collected during this aquatic assessment program will be used to determine reductions of
contaminant load into the Chena River from remedial actions and associated changes to
aquatic organisms. The annual cost of this sampling program is $350,000. For cost-
estimating purposes, it has been assumed that the postwide sampling program will be
implemented every other year for 10 years. The frequency and scope of sampling will be
reviewed following the 1998 field season. gwmoe
5.4.1 Development of Remedial Alternatives
Remedial alternatives are developed by subarea for contaminant sources within WQFS
T™1 t!ematiVeS f°r WQFS1' WQFS2' and WQ*83 address so« containing DRO GRO
TA STV*1** eXfe
-------
DESCRIPTION OF ALTERNATIVES
TABLES
Remedial Alternatives for OU5 Source Areas
SubareaWQFSl . •:,£..:' • ; • . ... -^t-.. , ^A- :; : •,.'.:, .;.• JT-:/
1. No Action
2. Institutional Controls and Monitored and Evaluated Natural Attenuation
3. Source Area Treatment with Soil Vapor Extraction and Air Sparging, Institutional Controls, and Monitored
and Evaluated Natural Attenuation
4. Alternative 3 with Potential In Place Soil Heating at Source Areas
5. Alternative 4 with Operation of the Potential Downgradient Air Sparging Trench
1. No Action
2. Institutional Controls and Monitored and Evaluated Natural Attenuation
3. Hot Spot (Source Area) Treatment with Soil Vapor Extraction and Air Sparging, Continued Operation of the
Downgradient Air Sparging Curtain, Groundwater Monitoring, Institutional Controls, and Monitored and
Evaluated Natural Attenuation
1. No Action
2. Institutional Controls and Monitored and Evaluated Natural Attenuation
3. Hot Spot (Source Area) Treatment with Soil Vapor Extraction and Air Sparging, Institutional Controls, and
Monitored and Evaluated Natural Attenuation
1. No Action
2. Continued Operation of the Building 1060 SVE/AS Treatability Study System, Institutional Controls, and
Monitored and Evaluated Natural Attenuation
3. Alternative 2 with Additional SVE/AS
4. Alternative 3 with Downgradient Air Sparging Trench
5. Alternative 3 with Downgradient Funnels and Gates and an Air Sparging Trench
Remedial Area 1A ,
1. No Action
2. Institutional Controls
3. Sampling, Soil Cover, and Revegetation with Institutional Controls
4. Excavation and Offsite Disposal of Lead-Contaminated Soil Through Defense Reutilization and Marketing
Office to RCRA-Permitted Transport, Storage, and Disposal Facility
ANC/TRM503.DOC/991040005 FINAL OU5 ROD 57
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DESC«PTK)H OF ALTERNATIVES
Remedial alternatives developed for the Remedial Area 1A source area address lead-
contaminated soil. Lead contamination in soil is predominantly located within the benned
areas surrounding the tanks. The contaminated soil contains lead at concentrations of
concern to human and ecological receptors if current land-use scenarios were different and
restrictions were not in place.
Descriptions of remedial alternatives for WQFS1, WQFS2, WQFS3, EQFS, and Remedial
Area 1A are presented in the following sections.
58 RHM.OUSROO ANCyrRM503.DOC*n040005
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DESCRIPTION OFM.T£fVHT?V£S
5.4.2 SubareaWQFSI
The following discussion describes the remedial alternatives developed for WQFS1.
5.4.2.1 Alternative 1-No Action
Under the no-action alternative, no active remedial measures are used to address
contamination. The no-action alternative does not include monitoring, site controls, or
decommissioning of existing wells and probes. Additionally, off-source migration would
not be monitored or controlled. Although natural attenuation would occur under this
alternative, it would not be measured or evaluated, because no sampling or monitoring
would be conducted.
Development of the no-action alternative is required by the NCP to provide a basis of
comparison for the remaining alternatives. This alternative serves as a baseline by reflecting
current conditions without any cleanup effort. The no-action alternative was evaluated
consistently with NCP requirements. No present worth, capital, operation and maintenance
(O&M), or groundwater monitoring costs are associated with the no-action alternative.
Capital Cost: $0
Annual O&M Cost: $0
Total Cost (30-year present worth): $0
5.4.2.2 Alternative 2-lnstitutional Controls and Monitored and Evaluated Natural Attenuation
This alternative includes monitoring natural attenuation of contaminants along with the use
of institutional controls to restrict local groundwater and land use. A conceptual design
layout of Alternative 2 is shown in Figure 4.
A long-term groundwater monitoring program would be developed and implemented until
RAOs are met. For cost-estimating purposes, the program was projected to continue for
30 years. The frequency of monitoring would be decided during the development of the
remedial action work plan for the QFS. On the basis of the magnitude of the source
contamination, it is not likely that RAOs would be achieved for this alternative.
Natural attenuation and monitoring likely would be required beyond the 30-year period.
Groundwater-use restrictions would include preventing the installation of groundwater
supply wells within contaminated plumes in shallow and deep groundwater on post.
Sign
Former Leaking Former Leaking
Pipeline , UST
Groundwater
Not to Scale
Groundwater
Monitoring Well
Figure 4. Alternative 2 for WQFS1, WQFS2,
WQFS3, and EQFS
ANC/TRM503.DOCV991040005
RNALOU5ROD 59
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DESCRIPTION OF ALTERNATIVES
However, institutional controls cannot be used to control groundwater for protection of
downgradient environmental receptors. Institutional controls are not effective in preventiv
contaminants from entering the Chena River. Land-use restrictions would included JnT
future land use to operations currently being conducted at the source areas. Groundwater-
and tad-use restrictions would be incorporated into the Fort Wainwright master plan and
would be implemented and monitored through the institutional control SOPs.
Capital Cost: $88,000
Annual O&M Cost: $70,000
Total Cost (30-year present worth): $2,180,000
5.4.2.3 Alternative 3-Source Area Treatment with Soil Vapor Extraction and Air Sparging
Institutional Controls, and Monitored and Evaluated Natural Attenuation
This alternative consists of installing SVE/AS wells to address soil, groundwater, and
floating-product contamination in the source area. It also includes the monitored and
evaluated natural attenuation for less-contaminated areas and institutional controls
described for Alternative 2. A conceptual design layout of Alternative 3 is shown in
rigure 5.
The source-area SVE/AS system would strip VOCs from groundwater and soil and would
increase the potential for aerobic biological degradation of contaminants in saturated- and
vadose-zone soils. The SVE system would include offgas treatment. The SVE/AS wells
would be located within the contaminant source area. The horizontal AS well and the
horizontal SVE well that were installed as part of a treatability study system in WQFS1
would be operated as part of this alternative. This alternative also includes installation and
operation of an SVE/AS system in a treatability study east of the main treatment system
and just south of Gaffney Road scheduled for operation at the end of October 1998 This
treatability study is needed to evaluate the effectiveness of SVE/AS treatment. If the system
is effective, operation of the system will continue as part of the remedy.
Removal of VOCs from source-area soil is estimated to be complete within approximately
5 years, and the contribution of contaminants from source-area soil to groundwater would
Exhaust
Stack-.
Sign
Soil Vapor
Extraction
' Connex with Air Sparging &
Vapor Extraction Blower*
Monitoring
Former Leaking Former Leaking Well
Pipeline UST
Belowg round
Piping to Supply
Air and Withdraw
Vapors
Sparing
Not to Scale
Contaminated Groundwater
Figure 5. Alternative 3 for WQFS1, WQFS3, and EQFS
60 FINAL 005 ROD
ANC/TRM503.DOCI99104000S
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DESCRIPTION Of ALTERNATIVES
be significantly diminished after this time. This 5-year period for active treatment was
based on contamination degradation modeling for this area and has been used to estimate
costs. A review of Fort Wainwright SVE/AS systems in treatability studies indicated that
this period is a reasonable assumption.
Residual contamination in the form of low-volatility petroleum hydrocarbons likely would
remain in the source-area soil at concentrations above ADEC cleanup guidance. On the
basis of groundwater modeling, it is expected that the MCL for benzene would still be
exceeded at the Chena River after 10 years. Treatability studies at Building 1168 and other
sites suggest that the DRO cleanup rate in soil may become asymptotic at a concentration
greater than ADEC Level A. Contaminants in the soil (at concentrations exceeding ADEC
guidance) and groundwater in areas outside the inferred extent of floating product would
not be actively treated in this alternative. Monitored and evaluated natural attenuation
would be relied on to remediate these areas.
For cost-estimating purposes, it was assumed that groundwater monitoring would be
conducted in the source area during the 5 years of system operation and for an additional
3 years to monitor for contaminant rebound (8 years total). Natural attenuation monitoring
would be conducted during treatment of the contaminant source area and for an additional
25 years following source-area treatment (30 years total). This monitoring duration is based
on the following assumptions:
• Removal of VOCs from source soil is estimated to be complete within 5 years, and
source soil would no longer continue to act as a source of groundwater contamination
after this period. '
• Attenuation of COCs in soil and groundwater outside the defined treatment area to
concentrations below ARARs would occur after an additional 25 years.
The frequency of monitoring would be decided during the development of the remedial
action work plan for the QFS.
Alternative 3 also includes restrictions on local groundwater and land use until RAOs are
achieved. Groundwater-use restrictions would include preventing the installation of
groundwater supply wells in the plume areas and in downgradient areas where
contaminant migration might occur. However, institutional controls cannot be used to
control groundwater for protection of downgradient receptors. Institutional controls do not
effectively prevent contaminants from entering the Chena River. Land-use restrictions
would include limiting future land use to operations currently being conducted at the
source area. Groundwater- and land-use restrictions would be incorporated into the Fort
Wainwright master plan and would be implemented and monitored through the
institutional control SOPs.
Capital Cost: $3,371,000
Annual O&M Cost: $89,000
Total Cost (30-year present worth): $6,030,000
5.4.2.4 Alternative 4-Alternative 3 with Potential In Place Soil Heating at Source Areas
This alternative is the same as the Alternative 3 with the addition of in situ soil heating at
hot spot locations. A conceptual design layout of Alternative 4 is shown in Figure 6.
ANOTHM503.D00991M0005 FINAL OUS ROD 61
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0€SC«PT10N OF ALTERNATIVES
Exhaust
Stack,,
Sign
Connex with Air Sparging & Soil
Vapor Extraction Blowers
Hot Spot
Heating
Monitoring
Well
J
Belowg round
Piping to Supply
Mr and Withdraw
Vapors
Groundwater
Contaminated Groundwater
Not to Scale
Figure 6. Alternative 4 for WQFS1
In situ soil heating is proposed as a method to increase the speed and effectiveness of
remediation. In situ soil heating would be implemented in the areas containing the highest
contamination, specifically within the area that would be treated with the SVE/AS system
described in Alternative 3.
Two heating methods are being considered for OU5. These include radio frequency and six-
phase soil heating. Treatability studies are being conducted to evaluate the effectiveness of
these methods. For each of these basic methods, there are options for moderate-temperature
(40°C) and high-temperature (100°C) heating. Current information on these technologies
indicates that all four heating options (moderate- and high-temperature radio frequency
and moderate- and high-temperature six-phase soil heating) would be effective for
increasing the rate of contaminant removal in the WQFS1 source area. If results of the
treatability studies are favorable, in situ soil heating will be used at the areas containing the
highest contamination (hot spots).
Because treatability study results will not be available until 1999, one soil heating
technology has been selected to be representative for cost estimating. This choice does not
restrict the selection of the other options later in the remedial design when more
information is available from the treatability studies.
The SVE/AS of Alternative 4 is identical to that described for Alternative 3. By
supplementing source-area SVE/AS with in situ soil heating in areas with the highest
contamination, contaminant volatilization and biodegradation rates would increase and
RAOs would be achieved more rapidly. Residual contamination in the form of DRO likely
would remain in the source-area soil at concentrations above ADEC cleanup guidance;
however, adding soil heating to SVE/AS would increase the removal of DRO. A reduction
in treatment time may result in reduced O&M costs. The overall cost for remediation may in
turn be reduced if the savings in O&M costs are greater than the capital costs for
implementing in situ soil heating. The Army is currently conducting a treatability study
system of in situ soil heating at Fort Wainwright. If the system is effective, operation of the
system will be continued as part of the remedy.
62 FINAL OUS ROD
ANCrTRM503.DOC/991040005
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Preliminary information from the in situ heating treatability studies indicates that the time
required for treatment can be decreased substantially by augmenting SVE/AS with soil
heating. It is estimated that with moderate temperature heating (40°C) the contaminant hot
spot would be treated sufficiently in 2 years so that it would no longer act as a source of
VOC contamination to groundwater. Operation of the SVE/AS treatability system on the
eastern side of WQFS1 would continue to operate for 5 years because it does not include a
soil heating component.
Contaminants in the soil (at concentrations exceeding ADEC guidance) and groundwater in
areas outside the inferred extent of floating product would not be actively treated in this
alternative. On the basis of groundwater modeling, it is expected that the MCL for benzene
would still be exceeded at the Chena River after 10 years. It is expected that groundwater
outside the treatment areas would remain above MCLs for a long time.
Monitored and evaluated natural attenuation would be relied on to remediate these less-
contaminated areas (where contaminants in soil and groundwater are outside the inferred
extent of floating product). Natural attenuation in these areas may be enhanced by residual
heat in the soil heating areas.
For cost-estimating purposes, it was assumed that groundwater monitoring would be
conducted in the contaminant source area during the 2 years of system operation and for an
additional 3 years to monitor for contaminant rebound (5 years total). Monitoring outside
the contaminant source area for natural attenuation would be conducted during source-area
treatment and for an additional 28 years (30 years total). The frequency of monitoring
would be decided during development of the remedial action work plan for the QFS.
Restrictions on groundwater and land use are identical to those in Alternative 3.
Capital Cost: $3,650,000
Annual O&M Cost: $115,000
Total Cost (30-year present worth): $7,100,000
5.4.2.5 Alternative 5-Alternative 4 with Operation of the Potential Downgradient Groundwater
Air Sparging Trench
This alternative is the same as Alternative 4 with the possible addition of a downgradient
groundwater AS trench. A conceptual design layout of Alternative 5 is shown in Figure 7.
The AS trench would be either a line of vertical AS wells to form an AS curtain or would be
composed of a relatively high-permeability gravel fill about 30 feet deep with AS lines
installed at the bottom. The trench would be about 1,200 feet long and would be located just
south of Gaffhey Road. The AS trench would be installed to intercept and treat dissolved
contaminants migrating from the source area toward the Chena River.
Similarly to Alternative 4, the removal of VOCs from source-area soil is estimated to be
complete within about 2 years. The contribution of contaminants from source-area soil to
groundwater would be significantly diminished after this time. Because of the residual soil
contamination that would be present outside the active treatment area, migration of
contaminants from these areas to the groundwater would occur until these areas are
remediated by natural attenuation. The AS trench would provide treatment of this
groundwater until the source area is remediated. Residual contamination in the form of
ANOTHM503.DOQ991040005 FINAL OU5 ROD 63
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OESCT1PTION OF ALTERNATIVES
Exhaust
Stack
Connex with Air Sparging & Soil
Vapor Extraction Blowers
Hot Spot
Heating
Monitoring
Well
Former Leaking/' Former Leaking
pipeline
Bfllowg round
Piping to Supply
Air and Withdraw
Vapors
Not to Scale
Contaminated Groundwater
Figure 7. Alternative 5 for WQFS1
DRO likely would remain in the source-area soil at concentrations above ADEC cleanup
guidance.
On the basis of groundwater modeling, it is expected that the MCL for benzene would be
met at the Chena River in less than 10 years. It is expected that groundwater outside of the
treatment areas and upgradient of the AS trench would remain above MCLs for a longer
period of time.
For cost-estimating purposes, it was assumed that if in situ heating is implemented, source
area SVE/AS would be conducted for 2 years. If in situ soil heating is not implemented,
source area SVE/AS would be conducted for 5 years. Regardless of the duration of the
source-area treatment, the downgradient AS trench would operate for 30 years. It also was
assumed that groundwater monitoring would be conducted quarterly in the source area
during system operation and semiannually for an additional 3 years to monitor for
contaminant rebound. Natural attenuation monitoring of less-contaminated areas would be
performed during source-area treatment, during the 3 years after treatment is completed,
and during Years 10,15,20,25, and 30. The frequency of monitoring would be reevaluated
during development of the remedial action work plan for the QFS.
Restrictions on groundwater and land use are identical to those in Alternative 3.
Costs with heating:
Capital Cost: $3,610,000
Annual O&M Cost: $130,000
Total Cost (30-year present worth): $7,500,000
Costs without heating:
Capital Cost: $3,220,000
Annual O&M Cost: $111,000
Total Cost (30-year present worth): $6,540,000
FINAL OUS ROD
ANOTRM503.DOC/991040005
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DESCRIPTION OF AUERNATWES
5.4.3 SubareaWQFS2
A removal action was conducted in April 1998 after completion of the RI. The purposes of
this action were excavation and treatment of petroleum-contaminated soil in WQFS2 near
the Chena River retaining structure. The removal action resulted in source reduction (soil
and sediment) of free-product release to the Chena River by the following:
• Removal of the retaining structure
• Excavation and treatment of about 700 cubic yards of contaminated soil and sediment
• Excavation of soil down to the groundwater level and into the saturated zone
The removal action was expected to reduce the immediate source of floating product from
the bank of the Chena River. However, the removal action does not prevent floating
product from migrating from the hot spot in WQFS2 and recontaminating the area where
the removal occurred.
The following is a description of the remedial alternatives developed for WQFS2. These
alternatives have been developed in conjunction with the retaining-structure removal
action.
5.4.3.1 Alternative 1-No Action
This alternative is identical to the no-action alternative described for WQFS1.
5.4.3.2 Alternative 2-institutional Controls and Monitored and Evaluated Natural Attenuation
This alternative includes developing and implementing a long-term groundwater
monitoring program of natural attenuation. Figure 4 provides a conceptual design layout of
Alternative 2.
The frequency of monitoring would be decided during the development of the remedial
action work plan for the QFS. Monitoring likely would be required beyond the 30-year
period. Groundwater- and land-use restrictions are identical those described in Alternative
2 for WQFS1. On the basis of the magnitude of the source-area contamination, it is not
expected that Alternative 2 for WQFS2 would achieve RAOs.
Capital Cost: $60,000
Annual O&M Cost: $42,000
Total Cost (30-year present worth): $1,330,000
5.4.3.3 Alternative 3-Hot Spot (Source Area) Treatment with Soil Vapor Extraction and Air
Sparging, Continued Operation of the Downgradient Groundwater Air Sparging Curtain,
Groundwater Monitoring, Institutional Controls, and Monitored and Evaluated Natural
Attenuation
This alternative consists of installing SVE/ AS wells to address soil, groundwater, and
floating-product contamination in the hot spots (source areas), supplemented with a
downgradient groundwater AS curtain. The AS curtain was installed in 1998 adjacent to the
Chena River as part of a treatability study and would be operated as a component of this
alternative. The AS curtain primarily would address dissolved-phase contamination in the
groundwater, but also would provide treatment of floating product that may migrate from
ANC/TRM503.DOC/991M0005 FINAL OU5 HOD 65
-------
DESCRIPTION OF ALTERNATIVES
Exhaust
Stack
Sign
Connex with Air Sparging & Sol!
Vapor Extraction Blowers
Former Leaking Former Leaking
Pipeline , UST
Monitoring
Well
\
8*towaround
Piping to Supply
Qreundwater
Not to Scale
ndwater
rSpai
Wrt
.
rtl
Air Sparging Curtain
Treata Witty Study
Contaminated Groundwater
Figure 8. Alternative 3 for WQFS2
WQFS2 to the Chena River. A conceptual design layout of Alternative 3 is shown in
Figure 8.
The hot-spot (source-area) SVE/AS system would strip VOCs from soil and groundwater
and would increase potential for aerobic biological degradation of contaminants in
saturated- and vadose-zone soils. The SVE system would include offgas treatment. SVE/AS
wells would be located within the contaminant hot spot. The contaminant hot spot is
defined as the approximate extent of soil containing DRO, GRO, and BTEX at
concentrations that exceed the ADEC Level A cleanup concentrations. The SVE/AS system
would be installed so that the northern end of the system is directly adjacent to the area of
the removal action along the Chena River.
The downgradient groundwater AS curtain would consist of a series of closely spaced AS
wells. The AS curtain would provide treatment for dissolved contamination that would
migrate through the curtain toward the Chena River. Floating-product migration is
expected to be slowed by the AS curtain. Volatile components of the floating product would
be removed by the AS curtain, which would result in a reduced volume and a higher
viscosity for the floating product. AS also would result in a reduction in aquifer
permeability because of air being forced into previously saturated pore spaces, which
would decrease floating-product mobility. The AS curtain would not remove PAHs that are
contained in the floating product; however, it would slow their migration by slowing the
movement of the floating product. PAHs may be removed as a result of biodegradation,
which will be enhanced through AS.
Removal of VOCs from the contaminant source area is estimated to be complete within
about 5 years, and contribution of contaminants from soil to groundwater would be
significantly diminished in this time. This 5-year period for active treatment was based on
contamination degradation modeling for this area and has been used to estimate costs.
However, residual contamination in the form of low-volatility petroleum hydrocarbons
likely would remain in the soil at concentrations above ADEC cleanup guidance. The AS
curtain would operate simultaneously with the source remediation (5 years). It is expected
that the source-area treatment with SVE/AS and the AS curtain would also reduce the
66 FINAL 005 ROD
ANC/TRM503.DOC/991040005
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OESCfVPTKW OF ALTERNATIVES
migration of floating product (and therefore PAHs) to the area where the removal action
occurred. Therefore, this treatment also would reduce the migration of these components to
the Chena River. The time frame for this reduction and the extent of the reduction in
floating-product migration are difficult to estimate. Modeling for this area is continuing as
new data become available to more precisely define treatment time frames.
On the basis of groundwater modeling, it is estimated that the MCL for benzene would be
met at the Chena River in less than 10 years. The groundwater modeling assumes that
essentially all hot spots in WQFS2 would be treated by SVE/AS in this alternative.
Therefore, the modeling estimates that MCLs in the groundwater throughout WQFS2
would be met much more rapidly man for the nontreatment alternatives.
For cost-estimating purposes, it was assumed that hot spot treatment would be conducted
for 5 years, m addition, groundwater monitoring would be conducted quarterly in the hot
spot area during system operation and semiannually for an additional 3 years (8 years total)
to monitor for contaminant rebound. Natural attenuation groundwater monitoring of less-
contaminated areas outside the hot spots would be conducted during hot-spot treatment
(Years 1 to 5), during the 3 years after treatment is completed (Years 6,7, and 8), and in
Years 10,15,20,25, and 30. The frequency of monitoring would be reevaluated during
development of the remedial action work plan for the QFS.
This alternative also includes restrictions on local groundwater and land use until RAOs are
achieved. Groundwater-use restrictions would include preventing the installation of
groundwater supply wells in the plume areas and in downgradient areas where
contaminant migration might occur. However, institutional controls cannot be used to
control groundwater for protection of downgradient receptors. Institutional controls do not
effectively prevent contaminants from entering the Chena River. Land-use restrictions
would include limiting future land use to operations currently being conducted at the
source area. Groundwater- and land-use restrictions would be incorporated into the Fort
Wainwright master plan and would be implemented and monitored through the
institutional control SOPs.
Capital Cost: $1,070,000
Annual O&M Cost: $60,000
Total Cost (30-year present worth): $2,800,000
ANOmM503.DOC/991040005 FINAL OU5 ROD 67
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DESCaiPnOH OF ALTERNATIVES
5.4.4 Subarea WQFS3
The following is a description of the remedial alternatives developed for WQFS3.
5.4.4.1 Alternative 1-No Action
This alternative is identical to the no-action alternative described for WQFS1 and WQFS2.
5.4.4.2 Alternative 2-lnstitutional Controls and Monitored and Evaluated Natural Attenuation
This alternative is similar to Alternative 2 for WQFS1 and WQFS2 and includes
groundwater- and land-use restrictions. Figure 4 provides a conceptual design layout of
Alternative 2.
A long-term groundwater monitoring program would be developed and implemented until
RAOs are met. For cost-estimating purposes, this program was projected to continue for
30 years. The frequency of monitoring would be decided during development of the
remedial action work plan for the QFS. On the basis of the extent and magnitude of soil
contamination, this alternative would not likely meet RAOs.
Groundwater-use restrictions would include preventing the installation of groundwater
supply wells within shallow- and deep-groundwater contaminant plume areas and in
downgradient areas where contaminant migration might occur. However, institutional
controls cannot be used to control groundwater for protection of downgradient
environmental receptors. Institutional controls are not effective in preventing contaminants
from reaching the Chena River. Land-use restrictions would include limiting future land
use to operations currently being conducted at the source area. Groundwater- and land-use
restrictions would be incorporated into the Fort Wainwright master plan and would be
implemented and monitored through the institutional control SOPs.
Capital Cost: $71,000
Annual O&M Cost: $36,000
Total Cost (30-year present worth): $1,160,000
5.4.4.3 Alternative 3-Hot Spot (Source Area) Treatment with Soil Vapor Extraction and Air
Sparging, Institutional Controls, and Monitored and Evaluated Natural Attenuation
This alternative is similar to Alternative 3 for WQFS1 and consists of installing SVE/AS
wells to address soil and groundwater contamination in the source area.
The hot-spot (source-area) SVE/AS system would strip VOCs from groundwater and soil
and would increase the potential for aerobic biological degradation of contaminants in
saturated- and vadose-zone soils. The SVE system would include offgas treatment. SVE/AS '
wells would be located in the contaminant hot spot. The hot spot is defined as the
approximate extent of soil containing DRO and GRO at concentrations that exceed the
ADEC Level A cleanup concentrations. Figure 5 provides a conceptual design layout of
Alternative 3.
Removal of VOCs from source-area soil is estimated to be complete within about 5 years.
This 5-year period of active treatment was based on contamination degradation modeling
for this area and has been used to estimate costs. However, residual contamination in the
68 FINAL OU5 ROD AN
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DESCRIPTION Of ALTERNATIVES
form of low-volatility petroleum hydrocarbons likely would remain in the soil at
concentrations above ADEC cleanup guidance.
On the basis of groundwater modeling, it is estimated that the MCL for benzene would be
met at the Chena River in less than 10 years. The groundwater modeling assumes that
essentially all hot spots in WQFS3 would be treated by SVE/AS in this alternative.
Therefore, the modeling estimates that MCLs in the groundwater throughout WQFS3
would be met much more rapidly through treatment than in the nontreatment alternatives.
It is likely that some areas of soil contamination that would not be addressed by the
treatment system would be addressed over the long term by monitored and evaluated
natural attenuation.
For cost-estimating purposes, it was assumed that the hot-spot treatment would be
conducted for 5 years. In addition, it was assumed that groundwater monitoring would be
conducted quarterly in the hot spots during the 5 years of system operation and
semiannually for an additional 3 years to monitor for contaminant rebound (8 years total).
Natural attenuation monitoring of less-contaminated areas would be conducted during
system operation (Years 1 to 5), during the 3 years after system operation is discontinued
(Years 6 to 8), and in Years 10,15,20,25, and 30. The frequency of monitoring would be
decided during development of the remedial action work plan for the QFS.
Restrictions on local groundwater and land use are identical to those in Alternative 2.
Capital Gost: $440,000
Annual O&M Cost: $30,000
Total Cost (30-year present worth): $1,390,000
ANC/TRM503.0OCW91040005 FINAL OU5 ROD 69
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OESCTiPTON Of ALTERNATIVES
5.4.5 EQFS Source Area
The following are descriptions of the remedial alternatives for the EQFS source area.
5.4.5.1 Alternative 1-No Action
This alternative is identical to the no-action alternative described for WQFS1, WQFS2, and
WQFS3.
5.4.5.2 Alternative 2-Continued Operation of the Building 1060 SVE/AS Treatability Study
System, Institutional Controls, and Monitored and Evaluated Natural Attenuation
This alternative includes continued operation for 2 additional years of the SVE/AS
treatability study that is installed at Building 1060. It also includes monitoring natural
attenuation of less-contaminated areas and restricting local groundwater and land use.
The Bunding 1060 SVE/AS treatability study system addresses TCE, GRO, and DRO
contamination. The SVE/AS system, consisting of 12 vertical SVE wells and 10 vertical AS
wells, was installed in 1994 and has been effectively removing contaminants from soil and
groundwater. In general, the relatively high TCE concentrations encountered in soil
samples before startup were not detected in sample results after 1 and 2 years of operation.
For vadose-zone samples, the results show a reduction of contaminants at all sampling
locations. For saturated-zone soil samples, TCE has been reduced to low or nondetect levels.
TCE concentrations in groundwater were reduced by two orders of magnitude between
1993 and 1996. September 1997 groundwater monitoring results indicate TCE reductions of
42 to 97 percent from 1993 levels. The TCE concentration in downgradient groundwater is
now below the MCL of 5 ug/L.
For cost-estimating purposes, the Building 1060 treatment system would continue to be
operated for a total of 5 years from the time of startup (until the year 2000). Quarterly
groundwater monitoring of the treatment area would be conducted during system
operation and would continue semiannually for an additional 3 years after treatment is
discontinued to monitor contaminant rebound. Data are currently being evaluated to
identify the appropriate operation of the system.
On the basis of groundwater modeling, it is estimated that the MCL for benzene is currently
being met at the Chena River. However, MCL exceedances do occur at other locations
within EQFS. These areas would require a longer time to achieve RAOs.
A long-term groundwater monitoring program would be developed and implemented until
RAOs are met. For cost-estimating purposes, this program would be conducted during
system operation (Years 1 to 5), during the 3 years after the system is in place (Years 6 to 8),
and in Years 10,15,20,25, and 30. The frequency of monitoring would be decided during
development of the remedial action work plan for the QFS. Monitoring likely would be
required beyond the 30-year period until RAOs are met.
Groundwater-use restrictions also would be developed to include preventing the
installation of groundwater supply wells within shallow- and deep-groundwater
contaminant plume areas and in downgradient areas where contaminant migration might
occur. Land-use restrictions would include limiting future land use to operations currently
being conducted at the source area. Groundwater- and land-use restrictions would be
70 FINAL OUS ROD ANC/TRM503.DOC/991W0005
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DESCRIPTION Of ALTERNATIVES
incorporated into the Fort Wainwright master plan and would be implemented and
monitored through the institutional control SOPs.
Activities performed under this alternative will not affect the Ladd Field National Historic
Landmark District.
Capital Cost: $220,000
Annual O&M Cost: $35,000
Total Cost (30-year present worth): $ 1,290,000
5.4.5.3 Alternatives-Alternative 2 with Additional SVE/AS
This alternative consists of installing SVE and AS wells to address source-area soil,
groundwater, and floating-product contamination. Figure 5 is a conceptual design layout of
Alternative 3.
The SVE/AS system would strip VOCs from groundwater and soil and would increase the
potential for biological degradation of contaminants in saturated- and vadose-zone soils.
The SVE system would include offgas treatment. The SVE/AS wells would be located in the
areas where soil contamination exceeds ADEC Level A cleanup guidelines.
Removal of VOCs from soil is estimated to be complete within about 5 years. This 5-year
period of active treatment was based on contamination degradation modeling for this area
and has been used to estimate costs. The contribution of contaminants from soil to
groundwater would be significantly diminished after this time. However, residual
contamination in the form of low-volatility petroleum hydrocarbons likely would remain in
the soil at concentrations above ADEC cleanup guidance.
For cost-estimating purposes, it was assumed that groundwater monitoring would be
conducted at the treatment area during system operation and for an additional 3 years
(8 years total) to monitor for contaminant rebound. Natural attenuation monitoring of less-
contaminated areas would be conducted simultaneously with source-area treatment and for
an additional 25 years (30 years total).
Alternative 3 also includes restrictions on local groundwater and land use until RAOs are
achieved. Groundwater-use restrictions would include preventing the installation of
groundwater supply wells in the plume areas and in downgradient areas where
contaminant migration might occur. Land-use restrictions would include limiting future
land use to operations currently being conducted at the source area. Groundwater- and
land-use restrictions would be incorporated into the Fort Wainwright master plan and
would be implemented and monitored through the institutional control SOPs.
Capital Cost: $5,160,000
Annual O&M Cost: $120,000
Total Cost (30-year present worth): $8,760,000
5.4.5.4 Alternative 4-Alternative 3 with Downgradient Air Sparging Trench
This alternative supplements the Alternative 3 remedial measures with a downgradient
groundwater sparging trench along the south bank of the Chena River. The trench consists
of a highly permeable gravel fill about 30 feet deep with AS lines installed at the bottom
and SVE lines installed near the top. The AS trench is installed to intercept and treat
ANC/rRM503.DOO991040005 FINAL OUSflOO 71
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DESCfllPTlON OF ALTERNATIVES
dissolved contaminants migrating to the Chena River. A conceptual design layout of
Alternative 4 is shown in Figure 9.
As described in Alternative 2, groundwater near the Chena River is currently meeting
MCLs for benzene. On the basis of RI data and groundwater modeling, it is estimated that
the MCL for benzene is currently being met in shallow groundwater adjacent to the Chena
River and would continue to be met. The AS trench is not expected to remove a significant
amount of contamination from the groundwater.
As discussed for the previous alternative, removal of VOCs from source-area soil is
estimated to be complete within about 5 years. The contribution of contaminants from
source-area soil to groundwater would be significantly diminished after this time. Residual
contamination in the form of DRO likely would remain in the source-area soil at
concentrations above ADEC cleanup guidance. The AS trench would operate
simultaneously with the source-area remediation and for an additional 25 years (30 years
total). Groundwater monitoring would be conducted in the source area during system
operation and for an additional 3 years (8 years total) to monitor for contaminant rebound.
Natural attenuation monitoring of less-contaminated areas would be implemented until
RAOs are met. For cost-estimating purposes, monitoring was projected to continue for 30
years. The frequency of monitoring would be decided during development of the remedial
action work plan for the QFS.
Restrictions on groundwater and land use are identical to those in Alternative 3.
Activities performed under this alternative will not affect the Ladd Field National Historic
Landmark District.
Capital Cost: $5,378,000
Annual O&M Cost: $169,000
Total Cost (30-year present worth): $10,460,000
Exhaust
Stack.
Sk
Sign
Connex with Air Sparging & Soil
Vapor Extraction Blowers
Former Leaking Former Leaking
Pipeline UST
Monitoring
Well
Belowground
Piping to Supply
Air and Withdraw
Vapors
Gravel Filled Air
Sparging Trench
Groundwater
Not to Scale
Contaminated Groundwater
Figure 9. Alternative 4 for EQFS
FINAL 005 ROD
AN
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DESCRIPTION OF ALTERNATIVES
5.4.5.5 Alternative 5-Alternative 3 with Downgradient Funnels and Gates and an Air Sparging
Trench
This alternative supplements the Alternative 3 remedial measures with runnels and gates
along the south bank of the Chena River. A conceptual design layout of Alternative 5 is
shown in Figure 10.
A sheet-pile wall installed to a depth of about 30 feet would be designed to runnel
contaminated groundwater through openings, or gates, in the wall. As contaminated
groundwater passes through a gate, an AS trench installed in the gate area would reduce
contaminant concentrations.
As discussed for Alternative 3, operation of the source-area system is expected to last
5 years. The funnel-and-gate system would operate simultaneously with source remediation
and for an additional 25 years (30 years total). Groundwater monitoring of less-
contaminated areas would be conducted in the source area during system operation and for
an additional 3 years (8 years total) to monitor for contaminant rebound. Natural
attenuation monitoring would be implemented until RAOs are met For cost-estimating
purposes, this monitoring was projected to continue for 30 years. The frequency of
monitoring of less-contaminated areas would be decided during development of the
remedial action work plan for the QFS.
Restrictions on groundwater and land use are identical to those in Alternative 3.
Activities performed under this alternative will not affect the Ladd Field National Historic
Landmark District.
Capital Cost: $5,796,000
Annual O&M Cost: $162,000
Total Cost (30-year present worth): $10,640,000
Exhaust
SUcfc.
Connex with Air Sparging & Soil
Vapor Extraction Blowers
Former Leaking Former Leaking
Pipeline . UST
Monitoring
Well
Belowground
Piping to Supply
Air and Withdraw
Vapors
Contaminated Groundwater
Not to Scale
Sheet Pile Wall to
Funnel Groundwater
to Air Sparging Trench
cv;
*; Gravel Filled
',' Air Sparging
^Trench
Figure 10. Alternative 5 for EQFS
ANCTRM503.00O991040005
FINAL OU5 ROD 73
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DESCfUPTlON OF ALTERNATIVES
5.4.6 Remedial Area 1A
The following are descriptions of the remedial alternatives for the Remedial Area 1A source
area.
5.4.6.1 Alternative 1-No Action
Under the no-action alternative, no active remedial measures are used to address
contamination. The no-action alternative does not include monitoring and site controls.
Additionally, off-source migration would not be monitored or controlled.
Development of the no-action alternative is required by the NCP to provide a basis of
comparison for the remaining alternatives. This alternative serves as a baseline by reflecting
current conditions without any cleanup effort. The no-action alternative was evaluated
consistently with NCP requirements. No present worth, capital, O&M, or groundwater
monitoring costs are associated with the no-action alternative.
Capital Cost: $0
Annual O&M Cost: $0
Total Cost (30-year present worth): $0
5.4.6.2 Alternative 2-lnstitutional Controls
This alternative includes land-use and access restrictions. Soils containing petroleum and
other contaminants will be cleaned up when the tanks are removed under the conditions in
the Two-Party Agreement. Future land use is expected to be limited to activities associated
with an inactive fuel terminal. Access restrictions would include maintaining the existing
fence and posting signs. Land-use restrictions would be established and incorporated into
the Fort Wainwright master plan and would be implemented and monitored through the
institutional control SOPs. These restrictions are designed to limit the exposure of terrestrial
wildlife and to control trespassing in the restricted area. For cost-estimating purposes, it is
assumed that institutional controls would be maintained for 30 years.
Capital Cost: $8,000
Annual O&M Cost: $6,000
Total Cost (30-year present worth): $190,000
5.4.6.3 Alternative 3-Sampling, Soil Cover, and Revegetation with Institutional Controls
In this alternative, approximately four composite samples per tank and two samples at the
tank outfall area would be collected. It is estimated that 600 cubic yards of topsoil would be
placed on any existing lead-contaminated soils within the Remedial Area 1A area.
Revegetation would reduce the exposure to lead-contaminated soil. The volume estimate
was calculated assuming 10 feet around each tank area with soil cover to a depth of
6 inches. No additional sampling would be conducted after placement of the soil cover. The
soil placement and revegetation could be performed in one construction season. This
alternative also includes the same land-use and access restrictions as Alternative 2.
Capital Cost: $59,000
Annual O&M Cost: $6,000
Total Cost (30-year present worth): $240,000
74 IWM.OUSROD . ANCVTRMSOaDOC^MOOOS
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DESCRIPTION Of ALTEKNAmES
5.4.6.4 Alternative 4-Excavation and Offsite Disposal of Lead-Contaminated Soil Through
Defense Reutilization and Marketing Office to RCRA-Permitted Transport, Storage, and Disposal
Facility
Under this alternative, about 1,200 cubic yards of lead-contaminated soil would be
excavated. Most of this soil would have lead concentrations greater than 5 mg/L as
measured by the TCLP, and would be transported to a RCRA-permitted facility for storage
and disposal. The volume estimate was calculated assuming the soil to a distance of 10 feet
from each tank would be excavated to a depth of 1 foot. Additional sampling would be
performed to identify soils for removal and to refine the volume estimate before
remediation. Cleanup confirmation soil samples would be collected at the completion of
excavation. The remediation contractor would provide all equipment, services, and labor
required to sample, excavate, transport, treat, and dispose of the soil at the offsite RCRA-
permitted facility. Transport and disposal would be coordinated by the Defense
Reutilization Marketing Office. This alternative could be performed in one construction
season.
Capital Cost: $1,460,000
Annual O&M Cost: $0
Total Cost (30-year present worth): $1,460,000
ANC/TRM503.DOO991040005 FINAL OU5 ROD 75
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DESCRIPTION OF ALTERNATIVES
76 FWWtOUSROD
ANC/TRM503.DOC»9104<]005
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SECTION 6
Summary of Comparative Analysis
of Alternatives
In accordance with CERCLA, the alternatives for WQFS1 (five alternatives), WQFS2 (three
alternatives), WQFS3 (three alternatives), EQFS (five alternatives), and Remedial Area 1A
(four alternatives) were evaluated based on the nine criteria presented in the NCP. Table 10
lists the criteria. The first two criteria are known as threshold criteria and must be met by all
selected remedial actions. The following five criteria are known as balancing criteria, and
the final two criteria are referred to as modifying criteria.
TABLE 10
Criteria for Evaluation of Alternatives
THRESHOLD CRITERIA: Must be met by all selected alternatives.
1. Overall protection of human health and the environment. How well does the alternative protect human
health and the environment, both during and after construction?
2. Compliance with requirements. Does the alternative meet all applicable or relevant and appropriate state
and federal laws?
BALANCING CRITERIA: Used to compare alternatives.
3. Long-term effectiveness and permanence. How well does the alternative protect human health and the
environment after completion of cleanup? What, if any, risks will remain at the site?
4. Reduction of toxlcity, mobility, and volume through treatment. Does the alternative effectively treat the
contamination to significantly reduce the toxicity, mobility, and volume of the hazardous substances?
5. Short-term effectiveness. Are there potential adverse effects to either human health or the environment
during construction or implementation of the alternative? Howl long until remedial action objectives are
achieved?
6. Implementabllity. Is the alternative both technically and administratively feasible? Has the technology
been used successfully at similar areas?
7. Cost. What are the relative costs of the alternative?
MODIFYING CRITERIA: Evaluated as a result of public comments.
8. State acceptance. What are the state's comments or concerns about the alternatives considered and
about the preferred alternative? Does the state support or oppose the preferred alternative?
9. Community acceptance. What are the community's comments or concerns about the alternatives
considered and the preferred alternative? Does the community generally support or oppose the preferred
alternative?
ANCyrRM503.00Cfl91MQ005 FINAL OUS ROD Tl
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SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
6.1 SubareaWQFSI
6.1.1 Threshold Criteria
6.1.1.1 Overall Protection of Human Health and the Environment
Alternative 1, the no-action alternative, would not limit exposure to contaminants or reduce
contaminant levels, except through natural attenuation.
Alternative 2, institutional controls and monitored and evaluated natural attenuation,
would provide controls protective of human health for on-post receptors only. It would not
prevent migration of contaminants to the Chena River or provide protection for
downgradient receptors. This alternative is not considered protective of the environment.
Alternative 3 would protect human health and the environment by reducing source location
soil and groundwater contaminant levels to achieve remedial objectives, but would not
actively address the contaminant plume in downgradient shallow groundwater.
Alternative 4 is similar to Alternative 3 in its level of protection of human health and the
environment. However, Alternative 4 would treat the primary floating-product source area
more rapidly than Alternative 3 would because of the potential addition of in situ soil
heating. Alternative 4 would result in a faster reduction in the movement of contaminants
from the source to the groundwater. Alternatives 3 and 4 would result in similar levels of
protection, however.
Alternative 5 is the most protective of human health and the environment. It would provide
more rapid treatment of the source areas through SVE/ AS and potential enhancement of
treatment through in situ soil heating. It also would provide a method to capture shallow
contaminated groundwater that may result from small source areas that do not undergo
source treatment. The downgradient AS trench would provide this additional protection, if
necessary, for treating shallow groundwater until the smaller untreated source areas
undergo natural attenuation. Consequently, Alternative 5 would provide protection to the
Chena River much more quickly than the other alternatives. Deep groundwater would be
addressed by source control and natural attenuation. Monitoring would determine when
the RAOs are met, and institutional controls would prevent exposure of the groundwater
until these objectives are achieved.
6.1.1.2 Compliance with ARARs
All alternatives, except Alternatives 1 and 2, are intended to achieve ARARs for source-area
soil and groundwater and to reduce cancer risk from groundwater exposure for potential
future residents. Alternatives 4 and 5 are expected to achieve source-area ARARs sooner
than the other alternatives. Only Alternative 5 would address downgradient groundwater
contamination outside of the source area. Residual contamination in the form of low-
volatility petroleum hydrocarbons likely would remain in the source-area soil at
concentrations above ADEC cleanup guidance.
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SUMMARY OP COMPARATIVE ANALYSIS OF ALTERNATIVES
6.1.2 Balancing Criteria
6.1.2.1 Long-Term Effectiveness and Permanence
Alternatives 1 and 2 would not reduce residual risk, except through natural attenuation
over a long period of time. Alternatives 2 through 5 include groundwater monitoring, to
evaluate contaminant movement and determine the rate of natural attenuation. Alternatives
3,4, and 5 provide long-term effectiveness and permanence for soil and groundwater
treatment of the source area. However, Alternative 5 may achieve the highest degree of
effectiveness by intercepting and treating contaminant plumes in downgradient shallow
groundwater. The results of the groundwater treatability studies will be evaluated to
determine the effectiveness of these technologies.
6.1.2.2 Reduction of Toxicity, Mobility, and Volume Through Treatment
Alternatives 1 and 2 do not provide treatment and would not reduce toxicity, mobility, and
volume in soil or groundwater. Alternative 2 does account for long-term contaminant
reduction through natural attenuation.
Alternatives 3,4, and 5 would significantly reduce the toxicity, mobility, and volume of soil
and shallow-groundwater contamination in the source area. Alternative 5 is the only
alternative that would reduce the toxicity, mobility, and volume of contaminant plumes in
downgradient shallow groundwater through treatment. The toxitity, mobility, and volume
of deep-groundwater contamination would be reduced through source control and natural
attenuation.
6.1.2.3 Short-Term Effectiveness
Alternatives 1 and 2 do not provide treatment; therefore, they do not present additional
adverse risks to workers or the community. Remedial objectives would be achieved through
natural attenuation over a long time.
Risks to onsite workers and remedial contractors during the duration of construction for the
installation and implementation of Alternatives 3,4, and 5 would pose some short-term risk
that can be minimized with appropriate controls and measures. With of fgas treatment, risk
to the community from these alternatives is considered to be the same as for baseline
conditions. Alternative 3 is expected to achieve remedial objectives for soil in 5 years.
Alternatives 4 and 5 would achieve most RAOs within 2 years because they would treat the
hot spot more rapidly with in situ soil heating. Alternative 5 is expected to achieve remedial
objectives for shallow groundwater outside the contaminant source area more quickly than
any other alternative. In addition, Alternative 5 is most protective of the Chena River
because it minimizes additional contaminant releases to the river in the short and long term.
6.1.2.4 Implementability
All alternatives considered for WQFS1 are implementable. Source-area treatment
technologies are considered reliable, and the equipment and trained specialists are
available. In situ soil heating and the groundwater AS trench are considered new and
innovative but are implementable. Alternatives 1 and 2 are considered the most
implementable alternatives because of their simplicity. Alternatives 2 through 5 include
groundwater monitoring, which is technically and administratively feasible. Equipment,
specialists, and technology are readily available.
ANC/TRM503.DOC/991040005 FINAL OU5 ROD 79
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SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
6.1.2.5 Cost
The total costs of the alternatives are summarized in Table 11, which is provided at the end
of this section, and are based on the information available at the time the alternatives were
developed. These costs are estimated for the purposes of comparison and are considered to
be accurate within -30 to +50 percent Costs are described by using the 30-year present-
worth methodology with a discount rate equal to 5 percent Costs estimates include direct,
indirect capital costs, and annual O&M costs.
The cost of Alternative 1, no action, is $0. The cost of Alternative 2, institutional controls, is
$2,180,000. Of the alternatives expected to significantly reduce source-area toxicity,
mobility, and volume, Alternative 3, source-area treatment with SVE/AS, institutional
controls, and monitored and evaluated natural attenuation, is the least expensive
($6,030,000). The cost for Alternative 4 is $7,100,000. The cost for Alternative 5, which
provides reduction of toxicity, mobility, and volume in shallow downgradient
groundwater, is $7,500,000 with soil heating and $6,540,000 without soil heating.
6.1.3 Modifying Criteria
6.1.3.1 State Acceptance
The State of Alaska has been involved with the development of the remedial alternatives for
OU5 and concurs with the Army and the EPA in the selection of Alternative 5.
6.1.3.2 Community Acceptance
Although no official comments were received during the public comment period,
community response to the preferred alternatives was generally positive.
60 FINAL OU5 ROD ANCymM503.DOC/991040005
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SUMMARY OF COMPARATIVE ANALYSIS OFALTERNATtves
6.2 Subarea WQFS2
6.2.1 threshold Criteria
6.2.1.1 Overall Protection of Human Health and the Environment
Alternative 1, the no-action alternative, would not limit exposure to contaminants or reduce
contaminant levels except through natural attenuation. Alternative 2, institutional controls,
would provide controls protective of human health for potential on-post exposures only. It
would not prevent migration of contaminants into the Chena River or protect potential
downgradient users. These alternatives are not considered sufficiently protective of human
health and the environment.
Alternative 3 is the most protective of human health and the environment because it
addresses soil and shallow groundwater in the source area. This alternative treats the
source area through SVE/AS, which would reduce the VOC migration to the groundwater
and would also help to reduce floating-product migration to the Chena River. The
continued operation of the downgradient AS curtain would further reduce the migration of
these contaminants in the shallow groundwater to the Chena River. The level of
contaminant migration to the Chena and the time to achieve remediation in the source area
for this alternative would be significantly reduced compared to Alternatives 1 and 2.
Monitoring would determine when the RAOs are met, and institutional controls would
prevent exposure of the groundwater until these objectives are achieved.
6.2.1.2 Compliance with ARARs
Alternatives 1 and 2 would not achieve ARARs for soil and groundwater.
Alternative 3 is intended to achieve ARARs for soil and groundwater of contaminants in the
source area and addresses dissolved contamination in shallow groundwater downgradient
of the source area. Alternatives 2 and 3 address contamination in deep groundwater
through monitored natural attenuation.
6.2.2 Balancing Criteria
6.2.2.1 Long-Term Effectiveness and Permanence
Alternatives 1 and 2 would not reduce residual risk except by natural attenuation over a
long period of time. Alternatives 2 and 3 include groundwater monitoring for natural
attenuation. Alternative 3 would provide long-term effectiveness and permanence by
treating source-area soil and groundwater and intercepting and treating the contaminant.
plume in downgradient shallow groundwater. The results of the treatability study for the
groundwater AS curtain in WQFS2 would be evaluated to determine the degree of
effectiveness for this technology. The results of this treatability study are expected to be
positive.
6.2.2.2 Reduction of Toxicity, Mobility, and Volume Through Treatment
Alternatives 1 and 2 do not provide treatment and would not reduce toxicity, mobility, and
volume in soil or groundwater. Alternative 3 would significantly reduce the toxicity,
ANCnrRM503.DOC/991040005 RNALOU5ROD 81
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SIMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
mobility, and volume of soil and shallow-groundwater contamination in the source area
and the contaminant plume in downgradient shallow groundwater.
6.2.2.3 Short-Term Effectiveness
Alternatives 1 and 2 would not provide treatment; therefore, they would not present
additional adverse risks to workers or the community. Remedial objectives would be
achieved through natural attenuation over a long time.
Risks to onsite workers and remedial contractors associated with the installation and
implementation of Alternative 3 could be minimized with appropriate controls and
protective measures. With offgas treatment, risk to the community for these alternatives is
considered to be the same as for baseline conditions. Alternative 3 is expected to achieve
RAOs for source-area contamination in 5 years. Alternative 3 is most protective of the
Chena River because it minimizes additional contaminant releases to the river.
6.2.2.4 Implementability
All alternatives considered for the WQFS2 source-area treatment are implementable; (he
technologies are considered reliable; and the equipment and trained specialists are
available. The treatability study of the groundwater AS curtain would be evaluated to
determine curtain implementability and effectiveness. Alternatives 1 and 2 are considered
the most implementable alternatives because of their simplicity. Alternatives 2 and 3
include groundwater monitoring, which is technically and administratively feasible.
Equipment, specialists, and technology are readily available.
6.2.2.5 Cost
The cost for Alternative 1, no action, is $0. The cost for Alternative 2, institutional controls,
is $1330,000. Alternative 3, the only alternative expected to significantly reduce the toxicity,
mobility, and volume of source-area and downgradient groundwater, is estimated to cost
$2,800,000.
6.2.3 Modifying Criteria
6.2.3.1 State Acceptance
The State of Alaska has been involved with the development of the remedial alternatives for
OU5 and concurs with the Army and the EPA in the selection of Alternative 3.
6.2.3.2 Community Acceptance
Although no official comments were received during the public comment period,
community response to the preferred alternatives was generally positive.
82 RNALOUSROO ANC/TRMS03.DOO991M0005
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SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
6.3 SubareaWQFSS
6.3.1 Threshold Criteria
6.3.1.1 Overall Protection of Human Health and the Environment
Alternative 1, the no-action alternative, would not limit exposure to contaminants or reduce
contaminant levels, except through natural attenuation. Because no monitoring occurs in
this alternative, the degree of protection would not be known.
Alternative 2, institutional controls, would provide controls protective of human health for
potential on-post exposures only. However, Alternative 2 would not prevent migration of
contaminants into the Chena River or provide protection of downgradient receptors. These
alternatives are not considered sufficiently protective of human health and the
environment.
Alternative 3 is the most protective to human health and the environment. It provides
active treatment of the source area by SVE/AS, which is expected to immediately reduce
the migration of contaminants to the groundwater and achieve RAOs in about 5 years. The
level of contaminant migration to the Chena River and the time to achieve remediation in
the source area for this alternative would be significantly reduced compared to Alternatives
1 and 2. There would be no active treatment of the groundwater outside the source area.
However, natural attenuation is expected to lower the concentrations that reach the Chena
River and eventually result in groundwater that meets RAOs throughout the source area.
Monitoring would determine when the RAOs are met, and institutional controls would
prevent exposure of the groundwater until these objectives are achieved.
6.3.1.2 Compliance with ARARs
Alternatives 1 and 2 would not achieve ARARs for soil and groundwater.
Alternative 3 is intended to achieve ARARs for soil and groundwater of the contaminants in
the source area. It addresses dissolved contamination in downgradient groundwater
through monitored and evaluated natural attenuation.
6.3.2 Balancing Criteria
6.3.2.1 Long-Term Effectiveness and Permanence
Alternatives 1 and 2 do not reduce residual risk except through natural attenuation over a
long time. Alternative 2 includes groundwater monitoring for natural attenuation.
Alternative 3 would provide long-term effectiveness for source-area soil and groundwater
through treatment and addresses the contaminant plume in shallow groundwater outside
the source area through monitored and evaluated natural attenuation.
6.3.2.2 Reduction of Toxicity, Mobility, and Volume Through Treatment
Alternatives 1 and 2 do not provide treatment and would not reduce toxicity, mobility, and
volume in soil or groundwater. Alternative 2 would account for long-term contaminant
reduction through natural attenuation.
ANCTOM503.000991040005 ' FINAL OU5 HOD 83
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SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
Alternative 3 would significantly reduce the toxicity, mobility, and volume of soil and
shallow-groundwater contamination in the source area. It addresses the toxicity, mobility,
and volume of the groundwater contaminant plume outside the source area through
monitored and evaluated natural attenuation.
6.3.2.3 Short-Term Effectiveness
Alternatives 1 and 2 do not provide treatment; therefore, they would not present additional
adverse risks to workers or the community. Remedial objectives would be achieved through
natural attenuation over a long time.
Risks to onsite workers and remedial contractors associated with the installation and
implementation of Alternative 3 could be minimized with appropriate controls and
protective measures. With offgas treatment, risk to the community from these alternatives is
considered to be the same as for baseline conditions. Alternative 3 is expected to achieve
RAOs for source-area contamination in 5 years. In addition, Alternative 3 would reduce
contaminant load to the river in the interim.
6.3.2.4 Itnplementability
All alternatives considered for WQFS3 source-area treatment are implementable; the
technologies are considered reliable; and equipment and trained specialists are available.
Alternatives 1 and 2 are considered the most implementable because of their simplicity.
Alternatives 2 and 3 include groundwater monitoring, which is technically and
administratively feasible. Equipment, specialists, and technology are readily available.
6.3.2.5 Cost
The cost for Alternative 1, no action, is $0. The cost for Alternative 2, institutional controls
and monitored and evaluated natural attenuation, is $1,160,000. The cost for Alternative 3 is
$1,390,000.
6.3.3 Modifying Criteria
6.3.3.1 State Acceptance
The State of Alaska has been involved with the development of the remedial alternatives for
OU5 and concurs with the Army and the EPA in the selection of Alternative 3.
6.3.3.2 Community Acceptance
Although no official comments were received during the public comment period,
community response to the preferred alternatives was generally positive.
84 FINAL OU5 ROD ANCVTHM503.DOO991040005
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SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
6.4 EQFS Source Area
6.4.1 Threshold Criteria
6.4.1.1 Overall Protection of Human Health and the Environment
Alternative 1, the no-action alternative, would not limit exposure to contaminants or reduce
contaminant levels except through natural attenuation. Alternative 1 is not considered
sufficiently protective of human health and the environment
Alternative 2, continued operation of the Building 1060 SVE/AS treatability study system,
institutional controls, and monitored and evaluated natural attenuation, is considered
sufficiently protective of human health and the environment. Benzene and TCE
concentrations in the shallow groundwater adjacent to the Chena River are currently below
MCLs. In contrast to WQFS, EQFS presents minimal potential for contamination to move off
post. Continued operation of the Building 1060 SVE/AS treatability study system would
reduce the TCE concentrations in this hot spot. A longer time period would be required to
achieve RAOs in other hot spots that would not be actively treated and in the deep
groundwater. However, institutional controls would prevent human exposure to these
areas of elevated groundwater contamination while natural attenuation is occurring.
Monitoring would be conducted to determine the progress of natural attenuation and to
determine the length of time that the institutional controls would need to be in place.
Alternative 3 would protect human health and the environment by reducing the levels of
soil and groundwater contaminants in the source area to achieve remedial objectives, but
does not actively address contaminant plumes in downgradient shallow groundwater. This
alternative would achieve RAOs in the source area more rapidly than Alternative 2 would,
but would not be more protective in the long term.
Alternatives 4 and 5 would achieve RAOs in the groundwater outside the source area more
rapidly than other alternatives would. They would achieve RAOs within the source area
more rapidly than Alternative 2 would. In the long term, however, they are not expected to
be more protective of human health and the environment than Alternative 2.
6.4.1.2 Compliance with ARARs
Alternative 1, the no-action alternative, may achieve soil and groundwater ARARs over a
very long time because of natural attenuation; however, it would not provide protection of
human health and the environment during that time. Alternatives 2 and 3 are intended to
achieve ARARs for soil and groundwater in the source area and to reduce cancer risk from
groundwater exposure for potential future residents.
Alternative 2, continued operation of the Building 1060 SVE/AS treatability study system,
institutional controls, and monitored and evaluated natural attenuation, would take the
longest to achieve ARARs; however, groundwater-use restrictions would be sufficiently
protective of human health while natural attenuation proceeded. Because the contaminant
concentrations are lower in EQFS, the contaminants are not intersecting the Chena River
and they appear to be biodegrading. ARARS could be met effectively with Alternative 2.
Alternatives 4 and 5 are intended to achieve ARARs for soil and groundwater in the hot
spot and also to address dissolved contamination in shallow groundwater downgradient of
ANC/TRM503.00C/991040005 FINAL OUS ROD 85
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SUMMARY Of COMPARATIVE AHAIYSIS OF AOERHAT1VES
the source. The preferred method for remediating deep groundwater is monitored and
evaluated natural attenuation.
6.4.2 Balancing Criteria
6.4.2.1 Long-Term Effectiveness and Permanence
Alternative 1 would not reduce residual risk except through natural attenuation over a long
time. Alternative 2 would provide long-term effectiveness and permanence for soil arid
groundwater of the hot spot at Building 1060 and would reduce residual risk in other source
areas through natural attenuation. Alternatives 2 through 5 include groundwater
monitoring for natural attenuation.
Alternatives 3, 4, and 5 would provide long-term effectiveness and permanence for
treatment of source-area soil and groundwater. However, Alternatives 4 and 5 would
achieve the highest degree of effectiveness by intercepting and treating contaminant plumes
in downgradient shallow groundwater.
6.4.2.2 Reduction of Toxicity, Mobility, and Volume Through Treatment
Alternative 1 does not provide treatment; therefore, it would not reduce toxicity, mobility,
and volume in soil or groundwater except through natural attenuation.
Alternative 2 would provide treatment in the area of the Building 1060 SVE/AS treatability
study system, significantly reducing toxicity, mobility, and volume of contaminants in the
soil and groundwater in that area. In addition, Alternative 2 would reduce toxicity,
mobility, and volume of contaminants in soil and groundwater in other areas of EQFS
through natural attenuation.
Alternatives 3, 4, and 5 would significantly reduce the toxicity, mobility, and volume of soil
and shallow-groundwater contamination in the source area. Alternatives 4 and 5 would
reduce the toxicity, mobility, and volume of contaminated plumes in downgradient
groundwater.
6.4.2.3 Short-Term Effectiveness
Alternative 1 does not provide treatment; therefore, it would not present additional adverse
risks to workers or the community. Remedial objectives would be achieved over a long time
through natural attenuation.
Alternative 2 would provide continued operation of the Building 1060 SVE/AS treatability
study system. This system has operated successfully, and there are no increased short-term
risks from its continued operation. This alternative is expected to achieve RAOs in the
Building 1060 treatment area within 5 years. At the Chena River, cleanup goals are expected
to be met in less than 5 years. Outside of the active treatment area, Alternative 2 would
achieve RAOs over a longer time than in Alternatives 3, 4, and 5. However, as discussed
previously, short-term risks would be addressed by institutional controls and natural
attenuation.
Risks to onsite workers and remedial contractors associated with the installation and
implementation of Alternatives 3, 4, and 5, are essentially the same, and could be
minimized with appropriate controls and protective measures. With offgas treatment, risk
86 AN(VrRM503.DOC«91M0005
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SUUUMV OF COUPAMme ANALYSIS OF ALTEftHATtVES
to the community for these alternatives is considered to be the same as for baseline
conditions. Alternatives 3,4, and 5 are expected to achieve remedial objectives for soil and
shallow groundwater in the source area within 5 years.
6.4.2.4 Implementability
Alternatives 1 and 2 are considered the most implementable because of their simplicity.
Because contaminant concentrations are lower and because of the extensive underground
infrastructure in EQFS, construction and operation of active treatment systems would be
more difficult and less effective. Source-area treatment in Alternatives 3,4, and 5 is
considered implementable and effective. The downgradient groundwater AS trench and the
funnel and gate technologies in Alternatives 4 and 5 are considered new and innovative.
The Army is currently conducting a laboratory treatability study of the groundwater AS
trench to evaluate the effectiveness of this technology.
6.4.2.5 Cost
The cost of Alternative 1, no action, is $0. The cost of Alternative 2, continued operation of
the Building 1060 SVE/AS treatability study system, institutional controls, and monitored
and evaluated natural attenuation, is $1,290,000. Of the alternatives expected to significantly
reduce toxitity, mobility, and volume, Alternative 3, source treatment with SVE/AS,
institutional controls, and monitored and evaluated natural attenuation, is the least
expensive ($8,760,000). Alternatives 4 and 5 would provide additional reduction of toxicity,
mobility, and volume in downgradient shallow groundwater and cost $10,460,000 and
$10,640,000, respectively.
6.4.3 Modifying Criteria
6.4.3.1 State Acceptance
The State of Alaska has been involved with the development of the remedial alternatives for
OU5 and concurs with the Army and the EPA in the selection of Alternative 2.
6.4.3.2 Community Acceptance
Although no official comments were received during the public comment period,
community response to the preferred alternatives was generally positive.
ANC/TRM503.D00991040005 FINAL OU5 ROD 87
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SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
6.5 Remedial Area 1A
6.5.1 Threshold Criteria
6.5.1.1 Overall Protection of Human Health and the Environment
Alternative 1 would not provide protection of human health or environmental receptors.
Alternative 2 and Alternative 3 would reduce the risk to human health and ecological
receptors by reducing exposure to onsite contamination. These alternatives would meet the
RAO of minimizing direct contact with lead-contaminated soils containing more than 1,000
mg/kg of lead. Alternative 4 would provide the greatest protection of human health and
the environment by permanently eliminating the contaminants in the soil.
6.5.1.2 Compliance with ARARs
RCRA is an ARAR for all four alternatives. Alternative 1 would not meet compliance with
RCRA as an ARAR. Alternatives 2 and 3 would meet compliance with ARARs to the extent
that the RCRA corrective action permit for Fort Wainwright would integrate these
alternatives into permit requirements.
Guidance from the EPA Region 9 suggests no direct contact with lead-contaminated soil
that has concentrations grater than 1,000 mg/kg. Alternatives 2,3, and 4 meet the criteria of
this guidance. Alternative 4 would meet ARARs associated with disposal of lead-
contaminated soils.
6.5.2 Balancing Criteria
6.5.2.1 Long-Term Effectiveness and Permanence
Alternative 1 does not meet the intent of this criterion. Alternatives 2 and 3 would not
permanently eliminate long-term risks. However, the risk is controlled if current land-use
scenarios and access restrictions are maintained for both alternatives. Alternative 4 would
permanently eliminate risks related to lead-contaminated soil.
6.5.2.2 Reduction in Toxicity, Mobility, and Volume Through Treatment
Alternatives 1,2, and 3 would not actively reduce the toxicity, mobility, and volume of
contaminants at Remedial Area 1 A. Alternative 4 would permanently reduce the toxicity
and mobility of the contaminated soil:
6.5.2.3 Short-Term Effectiveness
Remedial activities for Alternatives 3 and 4 would create short-term impacts (dust) that
would require readily available controls. There are no short-term impacts for Alternatives 1
and 2. The time required to implement Alternative 2 would be minimal. Alternative 3
would require a small amount of lead time. Alternative 4 would take the longest to
implement, but could be conducted in one construction season.
6.5.2.4 Implementability
All the remedial alternatives are readily implementable.
88 FINAL OUS ROD ANC/TRM503.DOC/991M0005
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SUMMARY OF COMPARATIVE ANALYSIS OF ALTEBMATMES
6.5.2.5 Cost
The cost of Alternative 1, no action, is $0. The cost of Alternative 2, institutional controls is
$190,000. The cost of Alternative 3, sampling, soil cover, and revegetation with institutional
controls, is $240,000. Alternative 4, excavation and of fsite disposal of lead-contaminated soil
through Defense Reurilization and Marketing Office to RCRA-Permitted transport, storage,
and disposal facility, is the most expensive alternative at $1,460,000.
6.5.3 Modifying Criteria
6.5.3.1 State Acceptance
The State of Alaska has been involved with the development of the remedial alternatives for
OU5 and concurs with the Army and the EPA in the selection of Alternative 2.
6.5.3.2 Community Acceptance
Although no official comments were received during the public comment period,
community response to the preferred alternatives was'generally positive.
ANOTRM503.DOC/991040005 FINAL OU5 ROD 89
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SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
TABLE 11
WQFS, EQFS, and Remedial Area 1A Cost Comparison
Alternative
Average
Capital Annual O&M
Cost ($) Cost ($)
30-Year
Present-Worth
Total Cost ($)
Chens River Aquatic Assessment
Subarea WQFS1
1 No Action
2 Institutional Controls and Monitored and
Evaluated Natural Attenuation
0
88,000
3 Source Area Treatment with Soil Vapor Extraction 3.371.000
and Air Sparging, Institutional Controls, and
Monitored and Evaluated Natural Attenuation
4 Alternative 3 with Potential In Place Soil Heating 3,650,000
at Source Areas
0
70,000
89,000
115,000
5 Alternative 5 Without Soil Heating
Subarea WQFS3
3,220,000 111,000
0
2,180,000
6,030,000
7,100,000
6.540,000
Subarea WQFS2
1 No Action
2 Institutional Controls and Monitored and
0
60,000
0
42,000
0
1,330,000
1 No Action
2 Institutional Controls and Monitored and
Evaluated Natural Attenuation
0
71,000
0
36,000
0
1,160,000
90 FINAL 005 ROD
ANCmW503.DOC«91040005
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SUMMARY OF COMPARATIVE MALYSIS t
TABLE 11
WQFS, EQFS, and Remedial Area 1A Cost Comparison
Alternative
Average
Capital Annual O&M
Cost ($) Cost ($)
30-Year
Present-Worth
Total Cost ($)
EQFS Area
1 No Action
3 Alternative 2 with Additional SVE/AS
4 Alternative 3 with Downgradient Air Sparging
Trench
5 Alternative 3 with Downgradient Funnels and
Gates and an Air Sparging Trench
5,160,000
5,378,000
5,796,000
120,000
169,000
162,000
8,760,000
10,460,000
10,640,000
Remedial Area 1A
3 Sampling, Soil Cover, and Revegetation with
Institutional Controls
4 Excavation and Offsite Disposal of Lead-
Contaminated Soil Through Defense Reutilization
and Marketing Office to RCRA-Permitted
Transport, Storage, and Disposal Facility
59,000
1,460,000
6,000
0
Notes:
1. Costs are based on a 30-year present-worth analysis.
2. Discount rate applied is 5%.
= Selected remedy
240,000
1,460,000
ANC/TRM503.DOC/991040005
FINAL OU5 ROD 91
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SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
92 FINAL OU5 ROD
ANC/TRM503.DOC/991040005
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SECTION 7
II Selected Remedy
The selected remedies for WQFS, EQFS, and Remedial Area 1A were chosen on the basis of
the rune remedial alternative evaluation criteria found in the NCP as described in Section 6
The selected remedies for WQFS1, WQFS2, WQFS3; EQFS; and Remedial Area 1A are
presented in this section.
Natural attenuation is a component of the selected remedies for EQFS and all WQFS source
areas. These remedies also include the fundamental components of active remediation and
performance monitoring combined with institutional controls to ensure protection of
human health and the environment until contaminant concentrations are consistent with
unrestricted land use. The use of monitored natural attenuation was evaluated with the
same rigor as were other viable remedial approaches,-and will result in achieving goals of
source control and returning groundwater to its beneficial use.
Site-specific sampling and data analysis have been conducted to characterize the nature and
rates of natural attenuation processes at these source areas. Performance monitoring will
continue as long as contamination remains above required cleanup levels.
General response actions have not been developed for Chena River sediment or surface
water below the water line. Because sediment excavation or other treatment technologies
implemented in the river could result in significant degradation or destruction of habitat it
was agreed by the three parties identified in the FFA and through consultation with the
Alaska Department of Fish and Game that active remediation of surface water and
sediment below the water line will not be attempted. Instead, the approach for reducing
concentration of COCs and achieving RAOs in Chena River sediment and water at OU5 will
be to reduce sources of contaminant releases to the river through remedial activities at
contributing source areas and to continue the Chena River Aquatic Assessment Program.
7.1 Selected Remedies
7.1.1 Chena River Aquatic Assessment
After the postwide and the OU5-specific risk assessments were completed, it was
determined that an aquatic assessment should be conducted.
This postwide sampling program, called the Chena River Aquatic Assessment Program is
currently being implemented. The following are the major components of this program:
• Performing an aquatic assessment of the Chena River during the spring and fall This
assessment includes collecting water, sediment, and detritus (organic leaf litter) samples
and analyzing them for contaminants of concern and water chemistry.
• Collecting benthic macroinvertebrates such as insects and larvae and analyzing them
through toxicological studies and bioassays
ANC/TRM503.DOC/991040005
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SELECTED REMEDY
• Determining reductions of contaminant load into the Chena River from remedial actions
and associated changes to aquatic organisms
Possible remedial actions will be considered later if further evaluation of impacts to the
river shows unacceptable risks to aquatic organisms.
It is assumed that contaminant load and associated impacts to the Chena River will be
reduced through the selected remedial actions for the QFS areas. The aquatic assessment
program is designed to establish a baseline for water quality, contaminant concentrations,
and loading and ecological conditions and to measure changes in these parameters through
time. The data will be evaluated to identify trends and ensure remedial objectives are being
met. Results and progress will be evaluated during the 5-year review. During the first full-
term 5-year review from the signature date of the OU5 ROD, if the data or other
information not considered in the development of this ROD indicates significant impacts to
the Chena River, other remedial alternatives or assessment measures will be evaluated by
the Army and presented to the regulatory agencies through a technical memorandum
generated within 6 months of the 5-year review date.
The total estimated 30-year present worth of this sampling program is $1,560,000, based on
a biennial cost of $350,000 for 10 years. For cost-estimating purposes, it has been assumed
that the postwide sampling program will be implemented every other year for 10 years. The
frequency and scope of sampling will be reviewed following the 1998 field season.
7.1.2 Institutional Controls
Institutional controls are a component of the selected remedy for WQFS, EQFS, and
Remedial Area 1A. The definition of institutional controls as specified in the NCP at
40 CFR 300.430(a)(l)(iii)(D) is incorporated by reference into this ROD.
The FFA reflects the intent to have the ROD for OU5 serve as a comprehensive sitewide
document (see FFA, Attachment 1, page 6). The institutional-control actions at Fort
Wainwright will apply on a sitewide basis to all areas, including those in OUs 1,2,3,4,
and 5. The ROD requires the U.S. Army Alaska (USARAK) to develop standard operating
procedures (SOPs) to identify all land areas under restriction; identify the objectives that
must be met by the restrictions; and specify the particular restrictions, controls, and
mechanisms that will be used to achieve the identified objectives. These SOPs are intended
to help assure that the institutional controls selected in this and other OU RODs at Fort
Wainwright are carried out and remain in place until the EPA, ADEC, and USARAK
determine they are no longer needed to protect the public and the environment. Upon
concurrence by the EPA and ADEC, the SOPs will be incorporated by adoption as part of
the OUS ROD, to serve as a single sitewide source documenting all institutional controls
being implemented at Fort Wainwright. The SOPs are a component of this ROD and must,
at a minimum, include the following elements:
• USARAK has developed institutional control SOPs, with concurrence by the EPA and
ADEC, that apply to each OU at Fort Wainwright that has an institutional control as a
component of the selected remedy in the OU ROD. Components of the SOPs are a
database with tracking mechanism that identifies all land areas under restriction (for
example, use of a master base plan, master post maps, or a certified survey plat); the
FINAL OUS ROD ANCVTRM503.DOC/991040005
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SELECTED REMEOY
objectives to be met by the restrictions; and the particular restrictions, controls, and
mechanisms that will be used to achieve the identified objectives.
• Activities required by the SOPs are included as a component of the operable unit
remedy cost.
• USARAK will monitor compliance with the SOPs, which with concurrence of all the
parties could be modified to accommodate minor substantive changes, on an annual
basis throughout the time the ROD-required institutional controls are in effect, unless
another monitoring frequency is specified by unanimous agreement among the EPA,
ADEC, and USARAK.
• USARAK will notify both the EPA and ADEC before any change in a previously
identified land-use designation or restriction or a specific required activity.
• USARAK, as part of the O&M report for each OU, will assess the condition of areas at
Fort Wainwright subject to institutional controls. These inspections will determine the
effectiveness and protectiveness of all institutional controls and designated land uses,
and will ascertain whether the current land and groundwater uses in the area are
consistent with the institutional controls and all RAOs outlined in the relevant decision
document governing that site or OU. Results of any field inspection will be documented
in the annual O&M report submitted for the OU pursuant to the remedial action report.
• USARAK will notify the EPA and ADEC immediately on discovery of any unauthorized
activity that is inconsistent with the institutional-control SOPs. The USARAK will issue
a stop work or stop activity notice on discovery of any unauthorized work. The stop
work or stop activity notice will remain effective until the EPA, ADEC, and USARAK
determine a plan of action to resolve the unauthorized change.
• USARAK will notify the EPA and ADEC at least 6 months in advance about any
transfer, by sale or lease, of areas of Fort Wainwright that are subject to institutional
controls, to ensure adoption of such additional measures as may be needed to assure
continued compliance with institutional controls on such transferred property. Before
actual transfer of land management responsibilities to the Bureau of Land Management
or another federal agency or department or to a private party, the Army will provide
such transferee a written copy of installation master-planning documentation that
identifies all institutional controls remaining in force.
• SOPs will be a component of the 5-year review process.
7.1.3 SubareaWQFSI .
Alternative 5 is the selected remedy for WQFS1 because it best controls risk pathways and
provides protection of human health and the environment. Expansion of existing proven
technology will permanently reduce VOC contaminants in soil and groundwater. In situ
soil heating will increase the remediation rate. A downgradient AS trench will intercept and
control contaminant migration the Chena River. Monitoring and evaluation of natural
attenuation will assist in projecting remediation time frames. Institutional controls will
ANC/TRM503.DOC/991040005 FINAL OU5 ROD 95
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SELECTED REMEDY
ensure interim protection. This alternative meets ARARs and is cost-effective. Alternative 5
includes the following:
• Operating an SVE/AS system to address solvent and petroleum contamination in the
source-area soil and groundwater and the floating-product contamination. The source
area SVE/AS system can be tailored to strip VOCs from groundwater and soil and to
enhance biological degradation of contaminants in saturated- and vadose-zone soils +
while minimizing vadose-zone desiccation. An existing system, used for a treatability
study, will be expanded to address the source area. The SVE system will include offgas
treatment. Before operation of the SVE/AS system begins, abandoned buried fuel
pipelines within the subarea will be purged of residual fuel to eliminate the potential for
the lines to act as ongoing contaminant sources.
• Potential in situ heating at hot spots is proposed as a method to increase the rate of
remediation in comparison to source-area treatment without heating. In the event that
AS is ineffective in achieving progressive reduction of the VOC and petroleum
hydrocarbon concentrations in soils, in situ soil heating is proposed as a means to
increase the movement of VOCs and make them easier to extract. Treatability studies
involving radio-frequency soil heating and six-phase soil heating have been initiated in
WQFS1 to evaluate the potential to enhance performance of AS and SVE.
• Potentially supplementing the AS and SVE with the operation of a downgradient
groundwater AS trench, if necessary, to intercept and treat dissolved contaminants
migrating from source areas downgradient toward the Chena River.
• Establishing and maintaining institutional controls to ensure that until federal and state lip
MCLs are attained, the groundwater will not be used as a potable water source. ^^
Institutional controls include restrictions governing site access, onsite construction, and
well development or placement. They will be necessary as long as hazardous substances
remain onsite at levels that preclude unrestricted use. Current and future land use is
industrial; current and future groundwater use is designated for residential use.
Groundwater- and land-use restrictions will be incorporated into the Fort Wainwright
master plan. Administrative components of these institutional controls are discussed
further in Section 7.1.2.
• Monitoring of the natural attenuation of COCs in groundwater to track decreases in
concentrations to below ARARs and achievement of RAOs. The possible rebound of
contaminant concentrations after operation of remediation technologies has ceased also
will be monitored.
• Monitoring the performance of remedial treatment systems, as described above, to
optimize treatment system effectiveness and efficiency through system modifications
and/or enhancements as appropriate
• Monitoring and evaluation of the selected remedy, including natural attenuation, to
determine achievement of RAOs
>-
• Monitored natural attenuation for deep groundwater and areas not being actively
treated within WQFS1
96 FINAL OU5 ROD ANCyTRM503.0OC/991040005
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SELECTED RSUEDY
It is estimated that Alternative 5 will meet RAOs in the source area in 2 years and at the
Chena River in more than 10 years. Elimination of the source-area petroleum and VOC
contamination in the soil by AS and SVE with soil heating will minimize further
contamination of the groundwater. Use of the AS trench for removal of COCs from the
groundwater and soil will prevent continued contamination of the Chena River.
The total estimated 30-year present worth of this alternative with soil heating is $7,500,000,
including $3,610,000 for capital costs and $130,000 annually for O&M, groundwater
monitoring, and final decommissioning costs.
The total estimated 30-year present worth of this alternative without heating is $6,540,000,
including $3,220,00 for capital costs and $111,000 annually for O&M, groundwater
monitoring, and final decommissioning costs.
7.1.4 SubareaWQFS2
Alternative 3 is the selected remedy for WQFS2 because it best controls pathways of risk to
human health and the Chena River aquatic receptors.'Alternative 3 treats solvent and VOC
contamination with SVE/AS treatment in hot spots and continued operation of an AS
curtain to enhance removal actions completed in spring 1998. Groundwater monitoring and
evaluation will be used to monitor natural attenuation of dissolved-phase contaminants in
groundwater. Institutional controls including groundwater and land-use restrictions will
control pathways of exposure. Alternative 3 is expected to meet ARARs and is cost-
effective. Alternative 3 includes the following:
• Installing an SVE/AS system to address solvent- and petroleum-contaminated hot spots
in the soil and groundwater and floating-product contamination. The hot-spot SVE/AS
system can be tailored to strip VOCs from groundwater and soil and to enhance
biological degradation of contaminants in saturated- and vadose-zone soils. The SVE
system will include offgas treatment. Before operation of the AS and SVE system begins,
abandoned buried fuel pipelines within the subarea will be purged of residual fuel to
eliminate the potential for the lines to act as ongoing contaminant sources.
• Continuing to operate a downgradient AS curtain to intercept and remove dissolved-
phase contaminants from the groundwater, thus minimizing potential impacts to the
Chena River.
• Conducting groundwater monitoring to determine whether cleanup levels are achieved
and maintained downgradient of the AS curtain.
• Establishing and maintaining institutional controls to ensure that until federal and state
MCLs are attained, the groundwater will not be used, except for activities undertaken to
initiate the selected remedies detailed in this ROD. Institutional controls include
restrictions governing site access, onsite construction, and well development or
placement. They will be necessary as long as hazardous substances remain onsite at
levels that preclude unrestricted use. Current and future land use is industrial; current
and future groundwater use is designated for residential use. Groundwater- and land-
use restrictions will be incorporated into the Fort Wainwright master plan.
Administrative components of these institutional controls are discussed further in
Section 7.1.2.
ANCVTRM503.DOC/991040005 FINAL OUS ROD 97
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SELECTED REMEDY
• Monitoring of the natural attenuation of COCs in groundwater to track decreases in
concentrations to below ARARs and achievement of RAOs. The possible rebound of
contaminant concentrations after operation of remediation technologies has ceased also
will be monitored.
• Monitoring performance of remedial treatment systems, as described above, to optimize
treatment system effectiveness and efficiency through system modifications and/or
enhancements as appropriate
• Monitoring and evaluation of the selected remedy, including natural attenuation, to
determine achievement of RAOs
• Monitored natural attenuation for deep groundwater and areas not being actively
treated within WQFS2
Alternative 3 is expected to meet the RAOs in the treated source area in 5 years and at the
Chena River in 5 to 10 years. The hot-spot SVE/AS treatment system and the downgradient
groundwater AS.curtain are intended to intercept and remove dissolved-phase
contaminants from the groundwater, thus minimizing potential impacts to the Chena River.
Groundwater monitoring will be conducted to determine whether cleanup levels are
achieved and maintained by the hot-spot SVE/AS system and continued operation of the
downgradient groundwater AS curtain.
The total estimated 30-year present worth of this alternative is $2,800,000, including
$1,070,000 for capital and $60,000 annually for O&M, groundwater monitoring, and final
decommissioning costs.
7.1.5 SubareaWQFSS
Alternative 3 is the selected remedy for WQFS3 because it best controls risk pathways,
thereby protecting human health and the environment. Information already gained from
treatability studies in WQFS1 will be used during removal of solvent and VOC petroleum
hydrocarbons from soil and groundwater in hot spots with SVE/AS treatment.
Alternative 3 is expected to meet ARARs and be implementable and cost-effective.
Institutional controls will ensure protective use for site access, onsite construction, and well
development or placement. Alternative 3 includes the following:
• Installing AS and SVE wells to address solvent- and petroleum-contaminated hot spots
in the soil and groundwater and floating-product contamination. The hot-spot SVE/AS
system can be tailored to strip VOCs from groundwater and soil and to enhance
biological degradation of contaminants in saturated- and vadose-zone soils. The SVE
system will include offgas treatment. AS and SVE wells are located in the contaminant '
hot spot. Before operation of the SVE/AS system begins, abandoned buried fuel
pipelines within the subarea will be purged of residual fuel to eliminate the potential for
the lines to act as ongoing contaminant sources.
• Establishing and maintaining institutional controls to ensure that until federal and state
MCLs are attained, the groundwater will not be used, except for activities undertaken to
initiate the selected remedies detailed in this ROD. Institutional controls include
restrictions governing site access, onsite construction, and well development or
placement. They will be necessary as long as hazardous substances remain onsite at
98 FINAL OU5 ROD ANOTRM503.DOO991040005
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SELECTED HE*
levels that preclude unrestricted use. Current and future land use is industrial; current
and future groundwater use is designated for residential use. Groundwater- and land-
use restrictions will be incorporated into the Fort Wainwright master plan.
Administrative components of these institutional controls are discussed further in
Section 7.1.2.
• Monitoring of the natural attenuation of COCs in groundwater to track decreases in
concentrations to below ARARs and achievement of RAOs. The possible rebound of
contaminant concentrations after operation of remediation technologies has ceased also
will be monitored.
• Monitoring the performance of remedial treatment systems as described above, to
optimize treatment system effectiveness and efficiency through system modifications
and/or enhancements as appropriate
• Monitoring and evaluation of the selected remedy, including natural attenuation, to
determine achievement of RAOs
• Monitored natural attenuation for deep groundwater and areas not being actively
treated within WQFS3
Alternative 3 is expected to meet RAOs in the treated source area in 5 years and at the
Chena River in 5 to 10 years. Elimination of the hot spots of petroleum and VOC
contamination in the soil by AS and SVE will minimize further contamination of the
groundwater and prevent continued contamination of the Chena River.
The total estimated 30-year present worth of this alternative is $1,390,000, including
$440,000 for capital and $30,000 annually for O&M, groundwater monitoring, and final
decommissioning costs.
7.1.6 EQFS Source Area
Alternative 2 is the selected remedy for EQFS because it best controls the risk pathways for
soil and groundwater through continued operation of an existing treatment system that has
proven effective. In addition, monitoring for natural attenuation parameters to track
decreases in dissolved-phase contaminants and the implementation of institutional controls
to limit future land and groundwater use make this alternative protective, implementable,
and cost-effective. Alternative 2 includes the following:
• Continuing to operate the AS and SVE wells of the Building 1060 SVE/AS treatability
study system to address solvent- and petroleum-contaminated hot spots in the soil and
groundwater and floating-product contamination. The SVE system includes offgas
treatment.
• Establishing and maintaining institutional controls to ensure that until federal and state
MCLs are attained, the groundwater will not be used, except for activities undertaken to
initiate the selected remedies detailed in this ROD. Institutional controls include
restrictions governing site access, onsite construction, and well development or
placement. They will be necessary as long as hazardous substances remain onsite at
levels that preclude unrestricted use. Current and future land use is industrial; current
and future groundwater use is designated for residential use. Land-use restrictions
ANCVTRM503.DOCW1M0005 FINALOUSROO 99
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SELECTED REMEDY
include limiting future land use to operations currently being conducted at the source
area. Groundwater- and land-use restrictions will be incorporated into the Fort
Wainwright master plan. Administrative components of these institutional controls are
discussed further in Section 7.1.2.
• Monitoring of the natural attenuation of COCs in groundwater to track decreases in
concentrations to below ARARs and achievement of RAOs. The possible rebound of
contaminant concentrations after operation of remediation technologies has ceased also
will be monitored.
• Monitoring the performance of remedial treatment systems, as described above, to .
optimize treatment system effectiveness and efficiency through system modifications
and/or enhancements as appropriate
• Monitoring and evaluation of the selected remedy, including natural attenuation, to
determine achievement of RAOs
• Monitored natural attenuation for deep groundwater and areas not being actively
treated within EQFS
Alternative 2 is expected to meet RAOs in the treatability study area in 5 years. Elimination
of hot spots of VOC and petroleum contamination in the soil by continued operation of the
SVE/ AS treatability study at Building 1060 will minimize further contamination of the
groundwater. Monitored and evaluated natural attenuation also has been proven effective
in reducing contaminant concentrations.
The total estimated 30-year present worth of this alternative is $1,290,000, including
$220,000 for capital and $35,000 annually for O&M, groundwater monitoring, and final
decommissioning costs.
7.1.7 Remedial Area 1 A
Alternative 2 is the selected remedy under current land-use scenarios for the lead-
contaminated soil in Remedial Area 1A. This alternative best meets the nine CERCLA
criteria by minimizing the exposure pathways with a remedy that meets ARARs and is
implementable and cost-effective. The main component of Alternative 2, institutional
controls, includes land-use and access restrictions that are considered protective of human
health and the environment under current land use. Soils containing petroleum and other
contaminants will be cleaned up when the tanks are removed under the conditions of the
Two-Party Agreement.
Alternative 2 will control exposure and eliminate potential risk to human health and the
environment. Onsite future uses and human access will be controlled by imposing land-use
restrictions, posting warning signs, and maintaining existing fencing of contaminated areas.
Fencing is sufficient to prevent access to lead-contaminated soils and potential food sources
by terrestrial animals. Uptake of lead from food sources affected by lead-contaminated soils
is a major component of ecological risk to the red fox on the north side of the Chena River.
In addition to the remedial actions used to treat COCs, institutional controls (see
Section 7.1.2) will be used to prevent unacceptable exposure to contamination remaining at
tOO FINAL OU5 ROD ANC/TRM503.DOO991040005
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SELECTED REMEDY
source areas at concentrations above RAOs. Institutional controls to restrict site access and
control land use are designed to minimize human and ecological exposure to contaminants.
Institutional controls include restrictions governing site access and onsite construction.,
They will remain in effect as long as hazardous substances remain onsite at levels that
preclude unrestricted use. Current and future land use is industrial. Land-use restrictions
include limiting future land use to operations currently being conducted at the source area.
Land-use restrictions will be incorporated into the Fort Wainwright master plan.
Administrative components of these institutional controls are discussed further in
Section 7.1.2.
The total estimated 30-year present worth of this alternative is $190,000, including $8,000 for
capital and $6,000 annually for O&M.
7.2 Remedial Action Goals
The overall goal of a remedial action is to protect hurrian health and the environment from
contaminated media associated with the OU5 source areas. The remedial action goals will
provide the most effective mechanisms to meet state and federal MCLs for drinking water.
To facilitate selection of the most appropriate remedial actions, specific cleanup objectives
were developed for the source areas. These objectives specify the COCs in each medium of
interest, exposure pathways and receptors, and acceptable regulatory levels. Remedial goals
were developed for industrial use of soils and residential use of groundwater.
The final cleanup levels for soil, groundwater, sediment, and surface water are presented in
Table 12. The remediation goals presented in Table 12 were established for the specific
COCs that were determined to require remedial action. These goals are intended for the
areas where active remediation will occur.
The cleanup levels for COCs in soils are based on ADEC cleanup guidelines for petroleum
products and EPA-recommended guidance for lead-contaminated soils. Because soils
contaminated with VOCs and petroleum-related compounds are acting as a continuing
source of contamination to groundwater, the remedial action goal for in situ soils is active
remediation until contaminant levels in groundwater are consistently below state and
federal MCLs. The State of Alaska cleanup levels for UST petroleum-contaminated soil and
Tables B and B2 in 18 AAC 75 will be considered as a guideline for the treatment of in situ
soils.
The cleanup levels for COCs in groundwater are federal and state MCLs for drinking water
and Alaska Water Quality Standards for protection of freshwater, aquatic resources. When
federal or state standards are not available, the cleanup level is based on a risk-based
concentration (RBC) equivalent to an excess lifetime cancer risk of 1 x 10"6 for a residential-
exposure scenario. The cleanup levels for COCs in groundwater are protective of
downgradient residential, commercial, and municipal utility system well users.
Monitoring at the OU5 source areas would be conducted to ensure that RAOs are achieved.
The goals of this monitoring include, but are not limited to, the following:
• To ensure that migration of contaminated groundwater from the source areas to
downgradient aquifers or surface waters is reduced or prevented
ANOTRM503.DOC/991040005 ' FINAL OUS ROD 101'
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SELECTED REMEDY
TABLE 12
Remedial Action Objectives and Preliminary Remediation Goals for Operable Unit 5
Remedial Action Objective
Source Area
Chemicals of Concern
Remediation Goal
Basis
Soil
Environmental Protection
Prevent migration to groundwater of soil
contaminants that could result in groundwater
WQFS & EQFS
WQFS & EQFS
contamination and exceedances of federal MCLs and WQFS
nonzero MCLGs and to groundwater that is closely WQFS
hydrologically connected to surface water (such as WQFS
the Chena River) that could result in exceedances of WQFS & EQFS
Alaska AWQS in surface water.
Limit human health and terrestrial receptor exposure
to lead-contaminated soil.
Remedial Area 1A
DRO
GRO
Benzene
Ethylbenzene
Toluene
Xylenes
Lead
Active remediation of soils until
contaminant levels in
groundwater are consistently
below state and federal MCLs.
No direct contact for total lead
concentration greater than
1,000 mg/kg
ADEC18AAC75
and 18 AAC 75
ADEC cleanup •
levels and human
health and
ecological risk
assessment and
EPA Region 9
Industrial
Preliminary
Remediation Goal
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SELECTED REMEDY
TABLE 12
Remedial Action Objectives and Preliminary Remediation Goals for Operable Unit 5
Remedial Action Objective
Source Area
Chemicals of Concern
Remediation Goal
Basis
Groundwater
Environmental Protection
Restore groundwater to its beneficial uses within a
reasonable time frame. Reduce or prevent further
migration of contaminated groundwater from the
source areas to the downgradient aquifer or surface
water bodies that are closely hydrologically
connected by achieving MCLs (where there are no
nonzero MCLGs) and Alaska WQS.
For groundwater that is hydrologically connected to
surface water, Alaska WQS will apply for the
following Fresh Water Uses: (1)(A) Water Supply;
(1)(B) Water Recreation; and (1)(C) Growth and
Propagation of Fish, Shellfish, Other Aquatic Life,
and Wildlife.
Ensure no risk to aquatic receptors through control of
contaminant movement through the groundwater into
the Chena River.
Remove floating product to the extent practicable to
eliminate film or sheen from groundwater.
WQFS & EQFS
WQFS & EQFS
WQFS
WQFS & EQFS
WQFS
WQFS & EQFS
EQFS
EQFS
EQFS
RRO
DRO
GRO
1,2-DCA
Benzene
Toluene
Trichloroethene
1,2-Dibromoethane
bis(2-Ch!oroethyl) ether
1110ng/L
1500ug/L
1300 ng/L
5ug/L
1,OOOu.g/L
5ug/L
0.05 ng/L
0.0092 ng/L
Floating-product
petroleum hydrocarbons
Eliminate sheen
18AAC75
18AAC75
18AAC75
MCL
MCL
MCL
MCL
MCL
1x10-6 Risk
Clean Water Act,
18AAC75, and
Alaska WQS Fresh
Water Uses
Human Health
Prevent use of groundwater containing contaminants
at levels above Safe Drinking Water Act MCLs,
nonzero MCLGs, or the following Alaska WQS for
Fresh Water Uses: (1)(A) Water Supply; (1)(B) Water
Recreation; and (1)(C) Growth and Propagation of
Fish, Shellfish, Other Aquatic Life, and Wildlife.
Safe Drinking Water
Act
18AAC75
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SaECTED REMEDY
TABLE 12
Remedial Action Objectives and Preliminary Remediation Goals for Operable Unit 5
Remedial Action Objective
Source Area
Chemicals of Concern
Remediation Goal
Basis
Chena River Sediments
Reduce sources of contaminant releases to the
Chena River.
Continue aquatic assessment.
Contaminated sediments No concentrations of toxic
that contain all COCs substances or petroleum
identified in the postwide hydrocarbons and other
risk assessment contaminants in bottom
sediments allowed that cause
deleterious effects to aquatic life
Benthic macroinvertebrate
assessment to establish
baseline and to monitor aquatic
biotic integrity through time
Clean Water Act and
Alaska WQS for
Sediments
See Note 1
Chena River Surface Water
Meet Alaska WQS for the following Fresh Water
Uses: (1)(A) Water Supply; (1)(B) Water Recreation;
and (1)(C) Growth and Propagation of Fish, Shellfish,
Other Aquatic Life, and Wildlife.
TAH
TAqH
Petroleum hydrocarbons
10ng/L
15ng/L
Eliminate sheen
Clean Water Act and
Alaska WQS
Clean Water Act and
Alaska WQS
Clean Water Act
and Alaska WQS
All chemicals of concern
identified in the postwide
risk assessment
Benthic macro-invertebrate See Note 1
assessment to establish
baseline and to monitor aquatic
biotic integrity over time
Groundwater monitoring to Alaska WQS
assess reduction of contaminant
releases to the Chena River
Note:
1. Basis is the assessment endpoint for the Chena River Aquatic Assessment, which evaluates the integrity of the biotic community in Segment D of the river.
WQS = Alaska Water Quality Standards
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SELECTED REMEDY
• To indicate contaminant concentration and compliance with MCLs and Alaska Water
Quality Standards
• To ensure that natural attenuation is occurring at the source areas
• To provide information to modify selected remedies to enhance performance, as
appropriate
7.3 Five Year Review
CERCLA and NCP require that a review be conducted of all remedial actions that do not
achieve cleanup levels for unrestricted use be conducted every 5 years. The first 5-year
review will be in 2001, based on the statutory review trigger date for OU3, Fort Wainwright.
The 5-year reviews will be conducted in accordance with OSWER Directive 9355.7-02,
May 23,1991, Structure and Components of Five Year Reviews, and supplemental
guidance. This guidance requires conducting different levels of review for sources with
ongoing treatment and sources where waste is left in place. This 5-year review may result in
a decision that the remedies selected in this ROD are no longer protective and that
additional remedial action must be taken by the Army to ensure protection of public health
and the environment.
The 5-year review for all source areas, will include, but not be limited to, the following
components:
• Evaluation of whether the response action remains protective of public health and the
environment. Evaluation will consider the effectiveness of the technology for the
specific performance levels established in the ROD.
• Evaluation of whether remedial action treatment systems remain cost-effective and
technically sound
• Review of remedial action treatment systems to determine whether the remedy might
be replaced by other more state-of-the-art remedies that would remain protective at less
cost
• Assessment of current and reasonable future land use of the site and surrounding area
to ensure that the ROD assumptions of land use are still reasonable and consistent with
institutional controls specified in Section 7.1.2 of this ROD
• Evaluation of ecological exposure pathways to verify that the assumptions and
ecological risk evaluations completed remain valid
• Addition of any new sampling data into the source area databases
Sites that have waste left in place are subject to additional requirements under the 5-year
review. These requirements are specifically applicable to Remedial Area 1A where natural
attenuation is not expected to occur. These requirements are as follows:
• Collection and evaluation of all new lead-risk information and risk-assessment
approaches for evaluating lead risks recommended by the state, EPA, or Army. This
ANCmW503.D00991040005 RNAL005ROO 105
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SEtECTED REMEDY
new information may result in a human health risk assessment for lead exposure being
conducted for Remedial Area 1A.
• Collection and evaluation of current Army, EPA, and state regulations and policies on
remediation of lead in soils, keeping in mind that total lead values at Remedial Area 1A
reflect commingling of releases from numerous lead sources
• Any other new information, draft or otherwise, or considerations relevant to an
assessment of protectiveness for Remedial Area 1A
No less often than during the CERCLA 5-year reviews, the Army will evaluate the OB/OD
area. This evaluation will include review of the active range and any UXO within the
OB/OD area and range, to determine whether institutional controls to restrict land use and
protect human health and the environment are sufficient. The Army also will evaluate the
status of RCRA rules and regulations for military munitions ranges and UXO to determine
whether additional RCRA requirements must be met.
t06 RHALOU5ROO , ANOTRMS03.DOC/991040005
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SECTION 8
Statutory Determinations
The main responsibility of the Army, ADEC, and EPA under their legal CERCLA authority
is to select remedial actions that are protective of human health and the environment. In
addition, Section 121 of CERCLA, as amended by SARA, provides several statutory
requirements and preferences. The selected remedy must be cost-effective and use
permanent treatment technologies or resource-recovery technologies to the maximum
extent practicable. The statute also contains a preference for remedies that permanently or
significantly reduce the toxicity, mobility, and volume of hazardous substances through
treatment. Finally, CERCLA requires that the selected remedial action for each source area
must comply with ARARs established under federal and state environmental laws, unless a
waiver is granted.
8.1 Protection of Human Health and the Environment
The selected alternatives for WQFS1, WQFS2, WQFS3, and EQFS will provide long-term
protection of human health and the environment and satisfy the requirements of Section
121 of CERCLA. The selected alternative for Remedial Area 1A is protective of human
health and the environment under current land-use scenarios.
8.1.1 WQFS1,WQFS2,WQFS3, and EQFS
The selected remedies will provide long-term protection of human health and the
environment. Institutional controls will be implemented to restrict residential development
and access of the source areas through standard installation security to keep risk at a
minimum until RAOs are achieved. Treatment of the contamination will reduce future risk
associated with exposure to contaminated soil and groundwater, and it will minimize
further contamination and offsite migration of the groundwater. Natural attenuation of
remaining contaminants in the groundwater and soil will continue to occur. Groundwater
monitoring and evaluation will track not only the effectiveness of treatment systems but
also the progress of natural attenuation. Continuation of the Chena River Aquatic
Assessment Program will ensure protection of aquatic resources.
The selected remedies are consistent with the presumptive strategy for contaminated
groundwater through technology phasing and the use of the OSWER Natural Attenuation
Policy, which specifies natural attenuation be used as a reasonable and protective
component of a broader remedial strategy.
8.1.2 Remedial Area 1A
The selected remedy, institutional controls, will provide protection of human health and the
environment. Residential development and access will continue to be restricted.
Engineering and safety controls, such as maintaining fences around the source-area
perimeter to restrict access by humans and terrestrial animals, will be used. In addition,
signs will be installed to warn the public of the contamination and restrict human access.
ANOTRM503.DOC/991W0005 • FINAL OU5 ROD 107
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STATUTORY DETERMINATIONS
Land-use restrictions will be incorporated into the Fort Wainwright master plan and will be
implemented and monitored through the institutional control SOPs. The effectiveness of
these controls will be periodically evaluated.
8.2 Compliance with Applicable or Relevant and Appropriate
Requirements and To-Be-Considered Guidance
The selected remedies for the WQFS and EQFS source areas will comply with all ARARs of
federal and state environmental and public health laws, including compliance with all
location-, chemical-, and action-specific ARARs listed below.
8.2.1 Applicable or Relevant and Appropriate Description
An ARAR may be either "applicable" or "relevant and appropriate." Applicable
requirements are those substantive environmental protection standards, criteria, or
limitations promulgated under federal or state law that specifically address a hazardous
substance, remedial action, location, or other circumstance at a CERCLA site. Relevant and
appropriate requirements are those substantive environmental protection requirements
promulgated under federal and state law that, although not legally applicable to the
circumstances at a CERCLA site, address situations sufficiently similar to those encountered
at the CERCLA site so that the use of the requirements is well suited to the particular site.
The three types of ARARs are described below:
• Chemical-specific ARARs are usually health- or risk-based numerical values or
methodologies that establish an acceptable amount or concentration of a chemical in the
ambient environment.
• Action-specific ARARs are usually technology- or activity-based requirements for
remedial actions.
• Location-specific ARARs are restrictions placed on the concentration of hazardous
substances or the conduct of activity solely because the ARARs occur in special
locations.
The to-be-considered (TBC) requirements are nonpromulgated federal or state standards or
guidance documents that are to be used as appropriate in developing cleanup standards.
Because they are not promulgated or enforceable, TBCs do not have the same status as
ARARs and are not considered required cleanup standards. They generally fall into three
categories:
• Health effects information with a high degree of credibility
• Technical information about how to perform or evaluate site investigations or response
actions
• State or federal agency policy documents
108 FINAL OUS ROD ANOTRM503.DOO99t040005
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STATUTORY DETEBJUIA
8.2.2 Chemical-Specific Applicable or Relevant and Appropriate Requirements
The following chemical-specific ARARs have been identified:
• Federal Safe Drinking Water Act (40 CFR141) and Alaska Drinking Water
Regulations (18 AAC 80). The MCL and nonzero MCLGs were established under the
Safe Drinking Water Act and are applicable and relevant and appropriate for
groundwater that is a potential drinking water source. The MCLs and MCLGs will be
met through treatment and natural attenuation.
• Alaska Water Quality Standards for Protection of Class (1)(A) Water Supply, Class
(1)(B) Water Recreation, and Class (1)(C) Aquatic Life and Wildlife (18 AAC 70).
18 AAC 70.015 specifies that actions may not degrade water that is higher in quality
than the Alaska Water Quality Criteria (Alaska Water Quality Standards,
18 AAC 70.020). The Alaska Water Quality Standards require the protection of all
groundwater and surface water for specific uses, including water supply, recreation,
and aquaculture. These standards are considered applicable for remedial actions
conducted at the OU5 WQFS and EQFS source areas. Many constituents of groundwater
regulated by Alaska Water Quality Standards have identical MCLs in drinking water
regulations. Alaska Water Quality Standards also contain criteria for sediment. These
regulations are applicable to surface water and sediments and apply to groundwater
that is closely hydrologically connected to surface water.
• Alaska Regulations for Underground Storage Tanks (18 AAC 78, as amended through
January 22,1999). The State of Alaska has established cleanup requirements for
petroleum contamination from leaking USTs to protect groundwater. These regulations
are relevant and appropriate for the OU5 source areas.
• Alaska Oil and Other Hazardous Substances Pollution Control Regulations (18 AAC
75, as amended through January 22,1999). These regulations are applicable. Under
these regulations, responsible parties are required to clean up oil and hazardous
substance releases in Alaska.
Recent amendments to these regulations include the following:
• The applicability of 18 AAC 70, Alaska Water Quality Standards, was changed so
that these standards will apply only to surface water and associated sediments and
to groundwater demonstrated to be closely hydrologically connected to nearby
surface waters.
• Specific numeric cleanup levels for petroleum hydrocarbons in soil are risk based
and are different from the soil cleanup levels specified in the cleanup matrix of past
Alaska UST regulation (18 AAC 78)
• Updated 18 AAC 75 regulations will require the removal of free-product petroleum
to the maximum extent practicable, and will include risk-based numeric cleanup
levels for gasoline-range and diesel-range petroleum hydrocarbons in groundwater.
• Updated 18 AAC 75 regulations contain soil cleanup standards of 1,000 mg/kg for
total lead.
ANC/TRM503.DOC/991040005 FINAL OU5 ROD 109
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STATUTORY DETERMINATIONS
8.2.3 Location-Specific Applicable or Relevant and Appropriate Requirements
The following location-specific ARARs have been identified:
• UST Soil Stockpile Separation Distances. In 18 AAC 78, Underground Storage Tanks,
Article 3 contains cleanup standards that include separation distance requirements for
soil storage and disposal (18 AAC 78.311). These requirements may apply to remedial
actions selected in this ROD.
• Air Quality Prevention of Significant Deterioration. Air quality standards for
prevention of significant deterioration (PSD) of the air basin in the Fairbanks region are
location-specific relevant and appropriate requirements for treatment alternatives
generating offgas in the OU5 source areas. (See 40 CFR Parts 50 and 61, 18 AAC 15, and
18 AAC 50.)
• National Historic Preservation Act of 1966. Section A106, which is implemented by the
Advisory Council on Historic Preservation and the Army through regulations found in
36 CFR 800 through 800.15, 16 United States Code 470 et seq., and Public Law 89-665;,
requires federal agencies to take into account the effects of the agency's undertaking on
properties included in or eligible for the National Register of Historic Places and, before
approval of an undertaking, to afford the State Historical Preservation Office and the
Advisory Council on Historic Preservation a reasonable opportunity to comment on the
undertaking. This statute is relevant and appropriate to the protection of the Ladd Field
National Historic Landmark/District.
8.2,4 Action-Specific Applicable or Relevant and Appropriate Requirements
The following action-specific ARARs have been identified:
• Federal Clean Air Act (42 United States Code 7401). As amended, these statutes are
applicable for venting contaminated vapors.
• Federal Air Quality Regulations. The substantive requirements of 40 CFR 61.93, air
emissions monitoring and procedures, are applicable to remedial actions for the OU5
source areas. Emissions resulting from the SVE/AS technology must be monitored
under the Fort Wainwright facility permit.
• Federal Clean Water Act. Section 404 of the Clean Water Act, which is implemented by
the EPA and the Army through regulations found in 40 CFR 230 and 33 CFR 320 to 330,
prohibits the discharge of dredged or fill materials into waters of the United States
without a permit.
• Alaska Air Quality Control Regulations. The substantive requirements of the ADEC
air-quality control regulations (18 AAC 50) must be satisfied at Fort Wainwright.
Remedial actions may produce organic vapors and fugitive dust, respectively, during
system operation. Emissions resulting from remedial technologies must be considered
and evaluated under the Fort Wainwright facility permit.
• RCRA Subtitle C. The RCRA Subtitle C (40 CFR 260-272) governs the "cradle-to-grave"
management of materials that meet the definition of a hazardous waste. Hazardous
wastes are either specifically listed in 40 CFR 261 Subpart D, or exhibit one of four
hazardous characteristics: ignitability, corrosivity, reactivity, or toxicity as determined
110 FINAL OU5 ROD ANC/TRM503.DOC/991W0005
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STATUTORY DETEBHINATKWS
by the TCLP. The most significant substantive RCRA requirements for a hazardous
waste generator include the following:
- 40 CFR 262.11-Applicable requirements to assess whether waste being generated is
a hazardous waste by sampling and analysis or process knowledge
- 40 CFR 262.34-Requirements applicable to the short-term (less than 90-day) storage
of RCRA hazardous waste (for example, excavated RCRA waste piles awaiting
treatment/disposal)
Excavated sediment (for the WQFS2 limited removal action), water removed in SVE
system flow streams, participate filters, or other wastes associated with OU5 source-
area remediation are not expected to meet the definition of a RCRA hazardous
waste. However if they do, the RCRA generator standards requirements, RCRA land
disposal restrictions (40 CFR 268), or RCRA treatment, storage, and disposal
requirements (40 CFR 264) will apply.
• Alaska UST Regulations for Underground Storage Tanks and Guidance (adopted by
reference as amended January 22,1999). ADEC UST regulations in 18 AAC 78 and the
Underground Storage Tanks Procedures Manual (December 10,1998) are relevant and
appropriate for the remediation of soil and groundwater with petroleum hydrocarbon
contamination at the OU5 source areas.
• Alaska Oil and Other Hazardous Substances Pollution Control Regulations (18 AAC
75), as amended through January 22,1999). These regulations are applicable and are
consistent with requirements in Alaska UST requirements.
• Alaska Solid Waste Management Regulations. Substantive provisions of Alaska
regulations for solid waste management (18 AAC 60) are identified as ARARs for
managing solid wastes that do not meet the definition of a RCRA hazardous waste.
Therefore, the following solid waste regulations may be relevant and appropriate to
excavated and/or treated soil and additional investigation-derived wastes:
- Disposal requirements for polluted soil (18 AAC 60.025)
- Accumulation, storage, and treatment of solid waste (18 AAC 60.010) (for example,
runoff and litter control and wildlife attraction control)
- Transportation requirements (18 AAC 60.015) (for example, containment of waste
and cleanup of any spills that may occur during transport)
8.2.5 To-Be-Considered Information
The following TBC information has been used in remedy selection and implementation:
• EPA Revised Interim Soil Lead Guidance for CERCLA Sites and RCRA Corrective
Action Facilities, OSWER Directive 9355.4-12 (1994)
• EPA Region 9 Industrial Preliminary Remediation Goals: no direct contact with lead
contaminated soil that has concentrations greater than 1,000 mg/kg
ANC/TRM503.DOO991040005 FINAL OU5 ROD 111
-------
STATUTORY DETERMINATIONS
• EPA Region 3 Risk-Based Concentration Tables
• OSWER Directive 9200.4-17, Use of Monitored Natural Attenuation at Superfund, RCRA
Corrective Action and Underground Storage Tank Sites
8.3 Cost Effectiveness
The Army believes that the combination of remedial actions identified as the selected
remedies for OU5 will reduce or eliminate the risks to human health and the environment
at an expected cost of $14.73 million. The remedies are cost-effective. They provide an
overall protectiveness proportional to their costs.
By tailoring the WQFS and EQFS remedies so that AS and SVE are applied in hot spots and
source areas and monitored and evaluated natural attenuation is performed in less-
contaminated areas, the selected remedies cost-effectively provide an appropriate level of
protection. Allowing monitored and evaluated natural attenuation to restore less-
contaminated areas within a reasonable time frame avoids costly and unnecessary remedial
action.
Institutional controls will be implemented at Remedial Area 1A. Land-use and access
restrictions cost-effectively provide an appropriate level of protection for humans and
terrestrial receptors.
8.4 Use of Permanent Solutions and Alternative Treatment
Technologies or Resource Recovery Technologies to the
Maximum Extent Practicable
The Army, ADEC, and EPA have determined that the selected remedies represent the
maximum extent to which permanent solutions and treatment technologies can be used in a
cost-effective manner at the OU5 source areas. Of those alternatives that protect human
health and the environment and comply with ARARs, the Army, ADEC, and EPA have
determined that the selected remedies provide the best balance of trade-offs in terms of
long-term effectiveness and permanence; reduction of toxicity, mobility, and volume
through treatment; short-term effectiveness; implementability; cost; and the statutory
preference for treatment as a principal element in considering state and community
acceptance.
8.5 Preference for Treatment as a Main Element
The selected remedies for WQFS and EQFS source areas satisfy the statutory preference for
treatment for soil and groundwater. The selected remedy for Remedial Area 1A does not
include active treatment as a main element. Under the current land use for this source area,
the chosen alternative is best and will effectively provide protection for human health and
ecological risks at the site.
112 ™*-OUSROD ' ANOTflMSOlDOCWIMOOOS
-------
SECTION 9
OB/OD Pad
9.1 Site History
The OB/OD area, formerly called the EOD area, is within the active small-arms impact
range on Fort Wainwright. The physical location is approximately 1,000 feet north of the
Tanana river and 1,500 feet south of the flood control dike. The bermed area measures about
150 feet by 450 feet. The OB/OD area was used by the Army from the mid 1960s to some
time between 1981 and 1986. The site was reportedly used for disposing of UXO and dud
ordnance, unused propellants (black powder), rocket motors, small-arms ammunition, and
other hazardous materials. Operating records are no longer available for this site.
The RCRA Facility Assessment indicated that the Fort Wainwright EOD Detachment
operates only occasionally and detonates less than 4,000 pounds of waste ordnance each
year. It notes the maximum explosive charge used to detonate munitions is a 50-pound
charge and is usually a C-4. During the winter months, the charge is reduced to 25 pounds
or less because of atmospheric conditions.
After extensive record searches, review of all available historical aerial photographs and
interviews with employees and past employees with an institutional knowledge of EOD-
OB/OD activities at Fort Wainwright, it was determined that the OB/OD site (formerly
identified as the EOD site) was the only historically active and identifiable ordnance
disposal area on Fort Wainwright. After ordnance disposal activities and procedures were
discussed with individuals who have local expertise, sampling was done by completing a
large array of analytical tests to identify any potential contaminants from historical
activities.
Field investigation and sampling were completed at the site on September 1,1994. Eight
surface soil samples (3 to 6 inches deep), one water sample, and appropriate quality
assurance/quality control samples were collected. Analysis was completed on all samples
for halogenated VOCs, DRO, pesticides and PCBs, chemical agents, organosulfur
compounds, explosives (and associated breakdown products), thiodiglycol, and
chloroacetic acid.
Additional samples were collected for metals analysis during the OU5 RI in 1996. Eight
surface soil samples (3 to 6 inches deep), along with to background samples from 1,100 feet
northwest of the OB/OB area, were collected from the approximate locations of the 1994
samples.
The U.S. Army Environmental Hygiene Agency (AEHA) identified this site as FA-113,
Explosive Ordnance Disposal Site, in the 1990 evaluation of solid waste management units.
The physical description provided in the AEHA document for the EOD site matches the
description for Site D-17, OB/OD pad, in the RCRA Facility Assessment (RFA), completed
in 1991. During the 1990 site investigation by AEHA, the site had several visible detonation
craters but no visible debris. The description states the site was used to detonate a small
ANCmW503.DOO991040005 FINAL OU5 ROD 113
-------
OB/00 PAD
amount of unserviceable munitions once a month. A visual inspection completed for the
RFA confirmed that no visible debris was present.
9.2 Physical Features
The soil within the OB/OD area is a permafrost silty clay. A water-filled gravel pit is
immediately adjacent to the OB/OD area. The RFA estimated contamination would be
predominantly lead, barium, and various nitrogen-rich, large-molecule,residuals from C-4,
large military rounds, and small-caliber munitions. It noted that the hazardous constituents
would be deposited in the first 18 inches of soil or in the open impact craters.
The sampling program at the OB/OD site was conducted to determine what, if any,
contamination existed at the site and at what levels. An observational approach was used to
identify sampling areas. This method focused on identifying the areas with the highest
potential for contamination.
Field representatives from the Army, EPA, ADEC, and U.S. Army Corps of Engineers,
accompanied by two ordnance experts, completed a site visit. With the assistance of the
ordnance experts, this reconnaissance team identified appropriate sampling locations. Soil
samples were collected at a depth of 3 to 6 inches below ground surface on the inside lip of
two detonation (impact) craters and from four areas where vegetation appeared stressed or
sparse. Initially, samples were only going to be collected in detonation craters. However,
during the field visit, the reconnaissance team agreed that the low vegetation areas also
should be sampled. One water sample was collected from a detonation crater. This sample
is considered representative of a groundwater sample, because the water level in the crater
was reflective of ground water elevation.
The sampling strategy-was designed to identify the worst-case contamination at the site. If
significant contamination had been found, additional sampling would have occurred.
9.3 Nature and Extent of Contamination
DRO was found in four soil samples at concentrations ranging from 5.3 to 21.0 mg/kg, well
below the most stringent potential ARAR of 100 mg/kg. The organosulfur compound
p-chlorophenyl methyl sulfoxide was the only other compound identified at this site. This
contaminant was found in three samples, with concentration ranging from 59 ug/kg to
657 ug/kg. This compound is reported to be a degradation product of the herbicide
Planevin. No ARARs or cleanup levels have been identified for this compound. No
screening criterion or surrogate risk analysis is available.
DRO also was found in the water samples at a maximum concentration of 0.19 ppm. No
other target analytes were identified.
Metals (arsenic, barium, cadmium, chromium, lead, mercury, selenium, silver, and
vanadium) were detected in each soil sample. Arsenic, cadmium, mercury, selenium, silver,
and vanadium were less than or equal to background levels. Barium, chromium, and lead
exceeded background levels, but were below Region 3 RBCs of 10"6 for soil.
\U FINAL OU5 ROD ANC/TRM503.DOC/991M0005
-------
06/00 PAD
9.4 Summary of Site Risks
The sampling program for the OB/OD area was designed to identify any released
contaminants from historical detonation activities. No contaminants that exceed any
ARARs or TBC criteria were identified at the OB/OD area. On the basis of the low levels of
DRO and the organosulfur compound (Planevin) identified, no risk assessment was
completed. The OB/OD area is within an active range, where human access is extremely
restrictive. The evaluation of the site indicated that there are no current complete exposure
pathways for contaminants and that the contaminants exist at such low levels that they are
not of concern. The low contaminant levels to not pose an unacceptable risk to human
health or the environment. An evaluation of future-use scenario for the site indicates that
the OB/OD area is likely to remain a small-arms impact range into the foreseeable future.
On the basis of the results of the RI/FS at the OB/OD area and an evaluation of data
collected at this site, no further action is selected for the OB/OD area for hazardous
chemicals. Because of concerns about potential human exposure to UXO, institutional
controls to monitor and control access and to restrict land use will apply to the OB/OD
area.
9.5 OB/OD Area Closure
The OB/OD area is being treated administratively as part of OU5 as agreed by the EPA,
ADEC, and Army in the 1992 FFA. This ROD selects the final remedial action for OU5, as
well as the EPA decision under RCRA hazardous waste closure of the OB/OD area at this
time.
The EPA, ADEC, and Army are electing to combine actions under RCRA and CERCLA
primarily because the OB/OD area is administratively subject to RCRA closure authority;
however, the OB/OD area is also a specified source area in OU5, which is subject to
CERCLA authority. Moreover, the OB/OD area is within the active firing range where
residuals of explosives remain. By applying CERCLA authority concurrently with RCRA
closure through this integrated plan, the EPA, ADEC, and Army intend to minimize
response costs and maximize protectiveness.
This ROD for OU5 integrates RCRA corrective action and the CERCLA remedial action
processes for describing and analyzing corrective and remedial alternatives. To fulfill the
requirements for the RCRA closure process, the Army will submit a closure plan in
accordance with procedures described in Section 9.6.
9.6 Closure Process
The OB/OD area was identified in the 1991 Federal Facility Compliance Agreement
(FFCA), signed by the Army and EPA, as a RCRA-regulated land-based unit. As such, the
OB/OD area is subject to the interim status standards codified in 40 CFR 265. Under the
1991 FFCA, the Army was required to submit a closure plan and a post-closure plan for this
unit in compliance with the interim status standards for closure codified in 40 CFR 265,
Subparts G and P. In addition, pursuant to the terms of the 1992 CERCLA FFA, the Army,
ADEC, and EPA agreed that RCRA corrective actions required at solid waste management
ANC/TRM503.DOC/991040005 FINAL OU5 ROD 115
-------
Oe/ODPAO
units at Fort Wainwright would be integrated with any ongoing CERCLA response actions,
but also agreed that such integration efforts would not relieve the Army of responsibility
for other hazardous waste activities for which federal law remained fully applicable. The
integration of RCRA corrective action and CERCLA response actions does not relieve the
Army from meeting RCRA closure and post-closure obligations for regulated units.
Although the OB/OD area is not currently active, EPA believes it is appropriate to allow
final RCRA closure of the OB/OD area concurrently with final clearance of the operating
range. Because the OB/OD area is physically part of the operating range and because it is
anticipated that UXO will continue to be present at the operating range, RCRA closure at
this time would be technically complex, with little, if any demonstrable environmental
benefit. The EPA is approving a delay of closure of the OB/OD area in accordance with
40 CFR 265.113(b)(l)(i). Delay of closure under this provision is subject to the requirements
of 40 CFR 165.1130?), which states, among other things, that final closure, by necessity, will
take longer than 180 days to complete.
Additionally, the facility must take, and continue to take,, all steps to prevent threats to
human health and the environment from the unclosed, but not operating, hazardous waste
regulated unit, including compliance with applicable interim status requirements, 40 CFR
265.113(b)(2). The Army has indicated, and the EPA agrees through the signing of this ROD,
that the OB/OD area meets the requirements for an extension of time for closure specified
in 40 CFR 265.113(b)(l)(i), provided that a draft interim closure plan and draft interim post-
closure plan acceptable to the EPA is completed by the Army as specified below. The Army
will submit, within 320 days from the date this ROD becomes final, a draft interim closure
plan and draft interim post-closure plan for the OB/OD area that meets the requirements
specified in 40 CFR 265, Subparts G and P. The draft interim closure plan and draft interim
post-closure plan will be developed and completed in accordance with the procedures for
submittal and review of primary documents specified in Paragraphs 20.12 through 21.11 of
the 1992 FFA. Final closure will occur under the authority of the 1991 FFCA, RCRA, and its
implementing regulations.
No less often than during the CERCLA 5-year reviews, the Army will evaluate whether
delay of closure is no longer viable for one of the following reasons:
• The active range is no longer operating.
• The post is being closed.
• Any other reason.
The findings of this evaluation will be submitted to the EPA for review and approval. If
either the EPA or the Army believe that delay of closure is no longer viable, the OB/OD
area will be closed under the substantive and procedural RCRA closure requirements in
effect at that time, and at that time, the Army will revise and resubmit the draft closure plan
and draft post-closure plan for the OB/OD area to the EPA for review and approval. Upon
approval of the final closure plan and final post-closure plan, the Army will close the
OB/OD area in accordance with the terms and conditions of that final closure plan and
final post-closure plan. In addition, the Army may elect to close the site under 40 CFR 265,
Subparts G and P, at any earlier time. This closure also will require compliance with all
substantive and administrative closure requirements, including EPA approval.
It6 FINAL OUS ROD ANOTRM503.DOO991040005
-------
SECTION 10
Documentation of Significant Changes
In the Proposed Plan, the OB/OD area was not identified as a RCRA-regulated unit subject
to closure. Subsequent review of the Administrative Record indicated that it is necessary to
close the OB/OD area in accordance with the administrative and substantive requirements
in 40 CFR 265, Subparts G and P, and in the 1991 FFCA. Section 9 of this ROD specifies the
process the Army will follow to close the OB/OD area.
ANC/TRM503.D00991040005 - FINAL OU5 ROD 117
-------
DOCUMENTATION OF SIGNIFICANT CHANGES
118 FINAL OU5 ROD
ANOTRM503.DOC/991040005
-------
Appendix A
Responsiveness Summary
ANC/TRM504DOC/99104001S • . FINAL OU5 ROD
-------
-------
APPENDIX A
Responsiveness Summary
Overview
The U.S. Army Alaska (Army), U.S. Environmental Protection Agency (EPA), and Alaska
Department of Environmental Conservation (ADEC), collectively referred to as the
Agencies, distributed a Proposed Plan for remedial action at Operable Unit 5 (OU5), Fort
Wainwright, Alaska. OU5 consists of six source areas: West Quartermaster's Fueling System
(WQFS), East Quartermaster's Fueling System (EQFS), Remedial Area 1A, Open
Burning/Open Detonation (OB/OD) Area, Motor Pool Areas, and Former Explosive
Ordnance Disposal (EOD) Range.
The Proposed Plan identified the preferred remedial alternative for WQFS, EQFS, and
Remedial Area 1A. No cleanup action was recommended for the OB/OD Area, Motor Pool
Areas, and Former EOD Range. Institutional controls that control groundwater and land use
and control access into Remedial Area 1A will continue.
The following are major components of the remedy selected for Subarea 1 of the WQFS
(WQFS1):
• In situ treatment of the source area with air sparging and soil vapor extraction to attain
state and federal standards for drinking water
• Potential in-place soil heating at hot spots, pending results of a treatability study to
increase contaminant removal
• Operation of the treatability study on the downgradient air-sparging trench to prevent
migration of contaminants to the Chena River and potential downgradient receptors
The following are major components of the remedy selected for Subarea 2 of the WQFS
(WQFS2):
• Hot-spot treatment with air sparging and soil vapor extraction to attain state and federal
standards for drinking water
• Continued operation of the downgradient air-sparging curtain to prevent migration of
contaminants to the Chena River
• Groundwater monitoring to determine downgradient concentrations
The following is the major component of the remedy selected for Subarea 3 of the WQFS
(WQFS3):
• Hot-spot treatment with air sparging and soil vapor extraction to attain state and federal
standards for drinking water
ANC/TRM5W.DOC/991040015 FINAL OU5 ROD A-1
-------
RESPONSIVENESS SUMMARY
The following is the major component of the remedy selected for EQFS:
• Continued operation of the treatability study of air sparging and soil vapor extraction at
Building 1060 to attain state and federal drinking water standards
All selected remedies for the EQFS and WQFS areas include the following:
• Institutional controls to restrict access, water use, and land use
• Monitored and evaluated natural attenuation to determine achievement of remedial
action objectives
The major component of the remedy selected for Remedial Area 1A is as follows:
• Institutional controls to restrict access and land use
No written comments and no verbal comments about the Proposed Plan for OU5 remedial
action were received during the public comment period.
Background of Community Involvement
The public was encouraged to participate in selection of the final remedy for OU5 during a
public comment period from June 17 to July 17,1998. The Proposed Plan for Remedial Action at
Operable Unit 5, Fort Wainurright, Alaska, presents options considered by the Agencies to
address contamination in WQFS, EQFS and Remedial Area 1 A. The Proposed Plan was
released to the public on June 16,1998, and copies were sent to all known interested parties,
including elected officials and concerned citizens. Informational Fact Sheets, prepared since
July 1993, provided information about the Army's entire cleanup program at Fort
Wainwright and were mailed to the addresses on the same mailing list.
The Proposed Plan summarizes available information about OU5. Additional information
was placed into two information repositories: the Noel Wien Library in Fairbanks and the
Fort Wainwright Post Library. An Administrative Record, including all items placed into
the information repositories and other documents used in the selection of the remedial
action, was established at the Directorate of Public Works in Building 3023 on Fort
Wainwright. The public was encouraged to inspect materials available in the Administrative
Record and the information repositories during business hours.
Interested citizens were invited to comment on the Proposed Plan and the remedy selection
process by mailing comments to the Fort Wainwright project manager, calling a toll-free
telephone number to record a comment, or attending and commenting at a public meeting
conducted on June 25,1998, at the Carlson Center in Fairbanks. The proceedings of the
meeting were recorded by a court reporter, and the transcript became a part of the
Administrative Record for OU5.
Basewide community relations activities conducted for Fort Wainwright, which includes
OU5, have consisted of the following:
• July 1992-communiry interviews with local officials and interested parties
• April 1993-preparation of the Community Relations Plan
A,2 ANC/TRM504.DOC/991040015
-------
RESPONSIVENESS SUMMHW
• July 1993-distribution of an informational Fact Sheet covering all OUs at Fort
Wainwright
• July 22,1993-an informational public meeting covering all OUs
• April 22,1994-establishment of informational repositories at the Noel Wien Library in
Fairbanks and the Fort Wainwright Post Library. Establishment of the Administrative
Record at the Directorate of Public Works in Building 3023 on Fort Wainwright.
• March 1995-distribution of an informational Fact Sheet covering all OUs at Fort
Wainwright
• September 1995-distribution of an informational Fact Sheet covering all OUs at Fort
Wainwright
• March 1996-distribution of an informational Fact Sheet covering all OUs at Fort
Wainwright
• January 1997-distributiori of an informational Fact'Sheet covering all OUs at Fort
Wainwright
• March 1997-distribution of an informational Fact Sheet soliciting interest from the
community for the formation of a Restoration Advisory Board (RAB) to support Fort
Wainwright. The fact sheet included a RAB membership application.
• September 1997-distribution of an informational Fact Sheet covering all OUs at Fort
Wainwright
• October 1997-revision of the Community Relations Plan
• October 14,1997-first meeting of the Fort Wainwright RAB
• January 13,1998-second meeting of the Fort Wainwright RAB
• March 31,1998-third meeting of the Fort Wainwright RAB
• June 1998-distribution of an informational Fact Sheet covering all OUs at Fort
Wainwright
• June 25,1998-fourth meeting of the Fort Wainwright RAB
Community relations activities specifically conducted for OUS included the following:
• June 15,1998-distribution of the Proposed Plan for final remedial action at OUS
• June 19, 21, 24, and 25,1998-display advertisement in the Fairbanks Daily News-Miner
announcing the public comment period and public meeting
• June 17 to July 17,1998-30-day public comment period for final remedial action at OUS.
No extension was requested.
• June 17 to July 17,1998-availability of a toll-free number for citizens to provide
comments during the public comment period. The toll-free number was advertised in
ANOTRM5M.OOC/991W0015 FINAL OUS ROD A-3
-------
RESPONSIVENESS SUMMARY
the Proposed Plan and the newspaper display advertisement that announced the public
review period. '
• June 25,1998-public meeting at Carlson Center in Fairbanks to provide information, a
forum for questions and answers, and an opportunity for public comment about OU5
Summary of Comments Received During the Public Comment Period and Agency
Responses
No comments were received during the public comment period.
A-« ANOTRM5M.OOC/991040015
-------
Appendix B
Administrative Record
ANC/TRM504 DOC/991 (MO015 FINAL OU5 ROD
-------
-------
ADMINISTRATIVE RECORD INDEX
OPERABLE UNIT 5
FORT WAINWRIGHT, ALASKA
Start
Page
20371
68439
68442
68530
71557
71700
71774
71782
71853
End
Page
20460
68441
68529
71556
71699
71773
71781
71852
71975
Date
11/12/91
3/1/97
3/12/97
11/22/96
3/7/97
8/1/97
3/1/97
11/15/96
1/17/97
Title
Fort Wainwright Comprehensive Environmental
Response, Compensation, and Liability Act Federal
Facilities Agreement.
Disposition of Review Comments Draft Work Plan
Operable Unit 5 West QFS Sub-Area WQFS2 Treatability
Study, Fort Wainwright, Alaska
Work Plan Operable Unit 5 West QFS Sub-Area WQFS2
Treatability Study, Fort Wainwright, Alaska
Operable Unit 5 Final Remedial Investigation Report, Fort
Wainwright, Alaska
Work Plan Operable Unit 5 Sub-Area WQFS1 Horizontal
Well Treatability Study, Fort Wainwright, Alaska
Intrinsic Remediation Treatability Study Work Plan, East
Quartermasters Fuel System Area, Delivery Order 14, Fort
Wainwright, Alaska
Disposition of Review Comments Draft Work Plan
Operable Unit 5 West WFS Sub-Area A Horizontal Well
Treatability Study, Fort Wainwright, Alaska
Fort Wainwright Operable Unit 5 Precision, Accuracy,
Representativeness, Completeness, and Comparability
Analysis Data Quality Assessment, Operable Unit 5
Remedial Investigation/Feasibility Study
Laboratory Bioremediation Study, Operable Unit 5, Fort
Wainwright, Alaska
OU
No.
IRP
5
5
5
5
5
3
i»
$
Category
No.
7.9
3.2
3.2
3.1.2
3.2
3.2
3.2
3.1.2
3.1.2
Author Name/Affiliation
Cynthia Mackey
USEPA
None given
HLA
S. Yancey and T. Gould
HLA
P. Ramert and G. Drewett
HLA
H. Hoen and T. Gould
HLA
Win Westervelt
CH2M HILL
None given
HLA
R. Howe and P.Ramert
HLA
Paul Ramert
HLA
Recipient
Name/Affiliation
Tamela Tobia
U.S. Army
None given
COE
Ted Bales
COE
Ted Bales
COE
Ted Bales
COE
Mark Wallace
COE
None given
COE
Ted Bales
COE
Ted Bales
COE
ANC/LKB69 DOC/960150010.DOC/1
FINAL OU5 ROD
-------
ADiMINISTRATIVE RECORD INDEX
OPERABLE UNIT 5
FORT WAINWRIGHT, ALASKA
Start
Page
71976
71978
71980
72IK2
7225')
72509
72565
72613
End
Page
71977
71979
72180
72258
72508
72564
72612
72649
Date
1/27/97
4/30/97
8/29/97
9/10/97
11/21/97
11/1/97
11/7/96
10/25/96
Title
Letter from Dianne Sodcrlund to Crista! Fosbrook re:
Comments on Three Precision, Accuracy,
Representativeness. Completeness, and Comparability
(PARCC) Analysis documents for Operable Units 2, 5 and
Postwide Risk Assessment Data, Fort Wainwright, Alaska
Letter from Wm. David Brown to Dianne Soderlund and
Rielle Markcy re: Army seeking extension for comments
on the Primary Document, Draft Feasibility Study,
Operable Unit 5. Fort Wainwright, Alaska
Quarterly Report Operable Unit 5 West Quartermaster's
Fueling System, Sub-Area 2 Oxygen Releasing Compound
Trcatability Study, Fort Wainwright, Alaska
Final Work Plan for 1997 Chena River Aquatic
Assessment Postwide Risk Assessment, For Wainwright,
Alaska
Operable Unit 5 Feasibility Study Fort Wainwright,
Alaska
Disposition of Review Comments Draft Remedial
Investigation Report Operable Unit 5, Fort Wainwright,
Alaska
Fort Wainwrighl Postwide Risk Assessment Precision,
Accuracy, Representativeness, Completeness, and
Comparability Analysis Data Quality Assessment
Fort Wainwright Postwide Risk Assessment Data
Validation Summary, Operable Unit 5, Fort Wainwright,
Alaska
OU
No.
5
5
5
b
5
5
5
5
Category
No.
3.3
4.5
3.2
3.1.1
4.2
3.1.2
8.0
8.0
Author Name/Affiliation
Dianne Soderlund
USEPA
Wm. David Brown
U.S. Army
H. Hoen and C. Wilson
HLA
None Given
ABR, HLA and
CH2M HILL
M. Schmetzer & J. McEIro
HLA
None given
HLA
R. Howe and S. Sexton
HLA
R. Howe and S. Sexton
HLA
Name/Affiliation
Cristal Fosbrook
DPW
D. Soderlund &
R. Markey
USEPA and
ADEC
Ted Bales
COE
Mark Wallace
COE
Ted Bales
COE
None given
COE
Ted Bales
COE
Rich Jackson
COE
AN" ••M)ioe.980150ni0in«..?
FINAL 0115 ROD
t
-------
ADMINISTRATIVE RECORD INDEX
OPERABLE UNIT 5
FORT WAINWRIGHT, ALASKA
Start
Page
72650
72664
72676
72679
51538
6185!
13180
13187
44345
61973
End
Page
72663
72675
72678
72832
52072
61972
13186
13194
47512
61974
Date
2/26/97
12/10/96
12/10/96
6/19/97
1 1/29/95
9/5/96
6/1/91
8/16/95
9/27/96
Title
Letter from Douglas Cox and Paul Ramert to Ted Bales re:
Conceptual Approach for Integrating Postwide Risk
Assessment Issues into the Operable Unit 5 Feasibility
Study, Fort Wainwrighl, Alaska
Disposition of Review Comments Draft Postwide Risk
Assessment, Fort Wainwright, Alaska
Minutes of Review Conferences Draft Postwide Risk
Assessment, Fort Wainwright, Alaska
Addendum to Operable Unit 5 Remedial Investigation
Report, Fort Wainwright, Alaska
North Airfield Groundwater Investigation (PSE), Fort
Wainwright, Alaska
Operable Unit 5 Magnetic Anomaly Test Pit Investigation
Site Safety and Health Plan, Work Plan and Responses to
Review Comments
OB/OD Range Closure Plan, Post-Closure Plan, and
Financial Requirements
Open Burning/Open Detonation Ground Sampling Plan for
FTWandFTR
Final Management Plan, OU5, Fort Wainwright, Alaska,
Remedial Investigation/Feasibility Study
Public Works Letter re: extension for the delivery of
Primary Document, RI/FS for Operable Unit 5
OU
No.
5
3
t> •
6
5
5
5
5
5
3
Category
No.
8.3
8.0
8.0
3.1.2
1.3.2
1.4.1 .
2.1.1
3.1
3.1.1
3.3
Author Name/Affiliation
D. Cox and P. Ramert
HLA
Various
HLA
Shaun Sexton
HLA
J. Ditsworth and P. Ramert
HLA
Karol Lorraine, J. Robert
HLA
Paul Ramert
HLA
None given
None given
None given
AEHA
Paul C. Ramert
HLA
Wm. David Brown
Public Works
Recipient
Name/Affiliation
Ted Bales
COE
Rich Jackson
COE
Rich Jackson
COE
Ted Bales
COE
Richard Jackson
COE
Rich Jackson
COE
None given
None given
Cristal Fosbrook
DPW
None given
COE
D. Soderlund and
R. Markey
USEPA & ADEC
ANC/LKB69.DOC/980150010.DOC/3
FINAL OU5 ROD
-------
ADMINISTRATIVE RECORD INDEX
. OPERABLE UNIT 5
FORT WAINWRIGHT, ALASKA
Start
Page
61975
61999
End
Page
61998
62034
Dale
7/18/96
6/28/96
Title
Alternatives Evaluation Report Operable Unit 5 Feasibility
Study, Fort Wainwright, Alaska
Remedial Action Objectives, Operable Unit 5 Feasibility
Study, Fort Wainwright, Alaska
OU
No.
5
5
Category
No.
4.2
4.2
Author Name/Affiliation
Paul Ramert and
Michael Sc
HLA
Paul Ramert
HLA
Recipient
Name/Affiliation
None given
COE
Richard Jackson
COE
ADEC = Alaska Department of Environmental Conservation
COE = U.S. Army Corps of Engineers
HLA = Harding Lawson Associates
USKI'A = U.S. Environmental Protection Agency
'69 l.'OC'9R01S0010 ix
FINAL OU5 ROD
e
•*
-------
f
*
Appendix C
No Further Action Sites and Fort Wainwright
CERCLA Federal Facility Agreement
Recommended Actions
ANC/TRM5W.DOC/99NM0015 FINAL OU5 ROD
-------
-------
APPENDIX C
No Further Action Sites and Fort Wainwright
CERCLA Federal Facility Agreement
Recommended Actions
Two source areas investigated in Operable Unit (OU) 5 have been identified for no further
action (NFA) under the Comprehensive Environmental Response, Compensation, and
Liability Act (CERCLA). The NFA source areas are as follows:
• Former Explosive Ordnance Disposal (EOD) Range (Blair Lakes Alpha Impact Area)
• Motor Pool Buildings
These source areas are shown in Figure C-1 on the following page.
Table C-1 lists the Motor Pool Buildings and describes the facilities and their current status.
This appendix also includes two signed Recommended Actions from the Federal Facility
Agreement (FFA), which identifies the authorities and responsibilities of the U.S.
Environmental Protection Agency, Department of the Army, and Alaska Department of
Environmental Conservation and integrates requirements under CERCLA. The
Recommending Actions are for the former EOD Range and the Motor Pool Buildings.
ANCyrRM5«.OOC/991«001S FINAL OU5 ROD C-1
-------
NO FURTHER ACTON SITES AND FORT WA1NWRK5HT CERCLA FEDERAL FACIUTY AGREEMENT RECOMMENDED ACTIONS
GaBneyRd. [ f' \.,
Figure C-1. No Further Action Sites
C-2 FINAL OUS ROD
ANC/TRM504.DOC/991040015
-------
NO FURTHER ACTIOfJ SITES AND TORT WAINWRIGHT CERCU FEDERAL FACILITY AGREEMENT RECOMMENDED,
CTK
TABLE C-1
Summary of Motor Pool Buildings and Current Activities
Building Number of
Number Motor Pools
Description of Motor Pool Facility
Status*
1053 and one each
1054
1168
one
3015
3421
3425
one
two
two
3479 two
3485 two
3487 one
Built in 1947 as a vehicle maintenance, repair, and
storage facilities. Drums contained oils, fuels, antifreeze,
and solvents. Diesel-range organics (DRO) were
detected in soil in both areas, but at concentrations
below established cleanup criteria. No evidence that soil
contamination from either area was posing unacceptable
risk to human health or the environment.
An air sparging (AS) and vapor extraction (VE) system
was installed to treat contamination from an underground
storage tank (UST). The system is currently being
monitored to assess the effectiveness of the remediation
system.
Excavated and thermally treated soils associated with
two UST removals in 1989. Alaska Department of
Environmental Conservation (AD EC) closure received for
the USTs. Recommended closure for eight seepage pits.
ADEC closure received for this site, which removed it
from the Two-Party Agreement
Isolated soil contamination, believed to be the result of a
surface spill, was excavated and thermally remediated
as part of a removal action in July 1997. ADEC
recommends semiannual groundwater monitoring to
determine whether upward trend of DRO contamination
is continuing.
ADEC closure received for this site, which removed it
from the Two-Party Agreement
ADEC closure received for this site, which removed it
from the Two-Party Agreement
On south side of post near Buildings 3479 and 3485
Soil-no further action
Groundwater-
addressed as part of
the East
Quartermaster's
Fueling System
Soil/groundwater-
continued operation
of the AS/VE system
Soil/groundwater-
no further action
Soil/groundwater-
no further action
Soil-recommended
for closure
Groundwater-
semiannual
monitoring
Soil/groundwater-
no further action
Soil/groundwater-
no further action
Unknown
' Status as agreed to in the NFA document being developed
ANC/TRM504.DOC/991040015
FINAL OUS ROD C-3
-------
-------
7 May 96
FORT WAINWRIGHT
CERCLA FEDERAL FACILITY AGREEMENT
RECOMMENDED ACTION
Source Area: Motorpools (13 estimated)
Recommended Action: Referral from Operable Unit 1 to Operable Unit 5
Background: A no further action document under CERCLA is being prepared. The
information needed to complete this actions is not complete in time to meet the
schedules of Operable Unit 1 . It was agreed by the Project Manager to move these
source areas to Operable Unit 5.
This decision document will become part of the Record of Decision (ROD) for Operable
Unit (OU) 2, as designated by the Federal Facility Agreement (FFA), which was signed
by EPA the Alaska Department of Environmental Conservation (ADEC) and the US
Army.
Comments:
Approvals: The following project managers, representing their respective agencies
which are signatories to the FFA, concur with this evaluation.
Rielle Markey Date
Alaska Department of Environmental Conservation
Remedial Project Manager
^DTanne Sodertund Date
US Environmental Protection Agency
Remedial Project Manager
Cristal Fosbrook Date
US Army, Alaska
Directorate of Public Works
Remedial Project Manager
-------
FORT WAINWRIGHT
CERCLA FEDERAL FACILITY AGREEMENT
RECOMMENDED ACTION
Source Area: Blair Lakes Alpha Impact Area.
Recommended Action: Referral from Operable Unit 1 to Operable Unit 5 and change
the name of the source to Former EOD Range.
Background: Based on a review of available historical information and interviews with
individuals having an institutional knowledge of Fort Wainwright it was determined that
this source consisted of a former open burning and open detonation area located in the
Alpha Impact Area. This source is listed in the RCRA Facility Assessment as Site D-
20, Former EOD Range, Alpha Impact Area. The current name of this source is broad
and does not adequately describe the source area.
Operable Unit 5 contains a similar type source area located within one mile of
this site. This source would be more efficiently investigated and remediated under this
operable unit.
Comments:
Approvals: The following project managers, representing their respective agencies
which are signatories to the FFA, concur with this evaluation.
t
^ _
RIELLE MARKEY ' 5- Date
Alaska Department of Environmental Conservation
Remedial Project Manager
Dianne Soderlund Date
US Environmental Protection Agency
Remedial Project Manager
i 3
Cristal Fosbrook Date
6th Division (Light), US Army Garrison
Directorate of Public Works
Remedial Project Manager
-------
Appendix D
Fort Wainwright Petroleum Strategy: Two-Party
Agreement Sites and Fort Wainwright CERCLA
Federal Facility Agreement
Recommended Action
ANC/TRM5M.OOC/99 104001 5
-------
-------
APPENDIX D
Fort Wainwright Petroleum Strategy:
Two-Party Agreement Sites and Fort
Wainwright CERCLA Recommended Action
This appendix provides supporting information for the strategies developed to clean up
petroleum contaminated sites at Fort Wainwright. A Two-Party Agreement between the
Department of the Army (Army) and the Alaska Department of Environmental
Conservation (ADEC) is part of the Federal Facility Agreement (FFA) for Operable Unit 5.
The Two-Party Agreement, which presents the petroleum cleanup strategy, documents all
known historical petroleum sources on Fort Wainwright and their current cleanup status. It
also verifies the Army's commitment to adequately address petroleum sites in a manner
consistent with state regulation.
Figure D-l and Table D-l identify the Two-Party Agreement sites.
Also included in this appendix is the Fort Wainwright Petroleum Strategy, which is an FFA
Recommended Action.
ANC/TRM504.DOC/991M0015 FINAL 005 ROD 0-1
-------
FORT WAIKWRK3HT PETROLEUM STRATEGY: TWO-PARTY AGREEMENT SfTES AND FORT WAINWRK3HT CERCU RECOMMENDED ACTION
Figure D-1.Two-Party Agreement Sites
0-2 FINAL OU5 ROD
ANC/TRM504.DOC/99104001S
-------
FOm WAINWHI6HT PETROUEUM STRATEGY: TWO-PARTY AGREEMENT SITES AND FORT WAINWRISHT CCRCU RECOMMENDED ACTOH
TABLE D-1
Two-Party Agreement Sites
POL Source Areas Recommended for Closure Discussions or Letters
• Building 1514 . Building 411OA
• Building 2092 . Petroleum Contaminated soil piles
• Building 3425 . Forward Air Refueling Point
• Building 4051
POL Source Areas Conducting Active Treatment or Institutional Controls
• Building 1002 . Building 2112
• Building 1168 . Building 2250
• Building 1546 . Building 3483
• Building 1599 . Building 3562
• Building 2060 • Building 3564
• Building 2062 • DRMO POL Sites
• Building 2063 . Birch Hill AST Tank Farm
• Building 2077 . North Post Sites 3 and 4
• Building 2111 -
POL Source Areas Referred to an Operable Unit
• Building 1053 • Building 1173
• Building 1059 . Building 1565
• Building 1060 . Building 3595
• Building 1070 • Pipeline Break North Post
POL Source Areas Undergoing Long-Term Monitoring
• Building 1172 . Building 5110
• Building 3481
POL Source Areas Closed Under the Two-Party Agreement
• Building 1056 • Building 3485
• Building 1191 . Building 3570
• Building 1541 . Building 3724
• Building 1543 . Building 4057
• Building 1563 . Building 4065
• Building 1594 * Building 4109
• Building 2080 . Building 411 OB
• Building 2106 . Building 4162
• Building 2108 . Building 4247
• Building 3015 . Building 5004
• Building 3403 . Birch Hill UST Sites
• Building 3421 . Contaminated Soil 1
• Building 3423 . Nike Sites B and C
• Building 3471 . Tar Sites
• Building 3479
ANOTRM504.DOC/991040015 RNALOU5ROO D-3
-------
ft
-ft
-------
Revised 12 January 1998
FORT WAINWRIGHT
CERCLA FEDERAL FACILITY AGREEMENT
RECOMMENDED ACTION
FORT WAINWRIGHT PETROLEUM STRATEGY
The objective of this document Is to confirm that Petroleum, Oil, and
Lubricant (POL) source areas, as Identified in the Army/Alaska Department of
Environmental Conservation (ADEC) Two-Party POL Agreement, including all
newly discovered petroleum sites to-date, are and will continue to be adequately
addressed under the Army/ADEC Two-Party Agreement (attached). This site
summary confirms that these sources are being adequately addressed under a
program and are not required to be included in the Remedial
investigation/Feasibility Study Management Plan, or subsequent investigations,
for Operable Unit (OU) 5, pursuant to Section 2.1 of Attachment 1 of the Fort
Wainwright Federal Facility Agreement (FFA). This document confirms that all
known POL historic sources at Fort Wainwright are being addressed under
either the Army/ADEC Two-Party Agreement or within an Operable Unit.
This document provides the mechanism for the inclusion of newly
discovered POL sources and the closure of all POL sources under the
Army/ADEC Two-Party POL Agreement.
Petroleum sites with soil and/or groundwater contamination have been
identified and updated in the Two-Party Agreement pursuant to Section 4.3 of
Attachment 1 of the FFA for Fort Wainwright The attached POL Strategy report
satisfies the requirements of this section. The POL report accurately reflects
current status of all identified POL sources at Fort Wainwright, other than those
being addressed through the CERCLA process, and is routinely updated.
Currently, 33 of the original 63 listed sites (all listed in the attached "POL
Two-Party Listed Sites Tracking Tables"), have received or will receive ADEC
closure, requiring no additional investigation. Seven of the 27 closed sites were
removed before 1988, prior to the promulgated regulations, removing the sites
from the ADEC closure requirements. AH of the 63 listed sites have been
investigated to determine the extent of contamination existing at the sites.
Corrective action plans are being discussed and implemented.
-------
FORT WA1NWRIGHT POL STRATEGY
Thirteen df the 63 listed sites are undergoing active remedial treatment, including
soil vapor extraction/air sparging, air injection, bioventing, bioremediation,
thermal desorption, or other technologies deemed appropriate by the remedial
project managers based on site-specific conditions. Three of the 63 listed sites
are undergoing intrinsic-remediation, to assess when remediation, through
natural attenuation, has occurred and when closure for the site can be
implemented. Eight of the 63 listed sites have been referred from the Two-Party
Agreement to be investigated and remediated in the Three Party Agreement,
under one of the five Operable Units.
. It is the goal of the Army, ADEC, and Environmental Protection Agency
(EPA) to proceed as follows:
• To assure that sites currently being addressed will continue to make
progress under the Two Party Agreement;
• To assure that newly discovered POL sites will be added to the Two
Party Agreement;
• To determine that ultimately, all identified POL sources will be
adequately addressed in a manner consistent with 18 AAC 78 and 18 AAC 75;
and
• To assure that continued funding for remediation of these sites will be
sought.
To accomplish these goals, the following actions will be taken:
• A meeting will be held on an annual basis, or more frequently if deemed
necessary, to update the Two-Party list. POL sources will appear on an annual
updated list, located in the Federal Facilities Agreement Appendices Section.
During this meeting, source status, remediation progress, source closure, and
schedules will be discussed;
• Site closure can occur through issuance of closure notices for
UST/LUST or a closure letter from the ADEC CERCLA Project Manager. When
closure occurs with alternate clean up levels, appropriate DEC approval will be
attained; and
• The Army will continue to request funding in accordance with Army
funding priorities and procedures.
-------
FORT WAINWRIGHT POL STRATEGY
Based on these criteria, it is determined that petroleum sources have
been and continue to be adequately addressed through the Army/ADEC Two-
Party POL Agreement and should not be included in the OU 5 Management Plan
or subsequent investigations. This document, as updated, will serve as a record
of actions taken and will be included in the Operable Unit 5 Record of Decision.
CONCURRENCE
APPROVALS: The following Project Managers, representing their respective
agencies which are signatories to the Federal Facilities Agreement, concur with
this strategy.
Rielle Markey " Date
Alaska Department of Environmental Conservation
Remedial Project Manager
Dianne Soderlund Date
U.S. Environmental Protection Agency, Region 10
Remedial Project Manager
3
Cristal Fosbrook Date
U.S. Army Alaska
Directorate of Public Works, Alaska
Remedial Project Manager
-------
-------
•*>
Appendix E
Operable Unit 5 Cost Estimates for
Remedial Alternatives
ANC/TRM504.00C/9910400t5 FINAL OU5 ROD
-------
-------
APPENDIX E
Operable Unit 5 Cost Estimates for Remedial
Alternatives
Baseline costs for the remedial alternatives presented in this Record of Decision (ROD) were
originally developed based on assumptions presented in the Final OU5 Feasibility Study (FS),
Fort Wainwright, Alaska Qune 1998). These estimated costs are expected to provide an
accuracy of +50 percent to -30 percent.
The capital and operations and maintenance costs for the selected alternatives have since
been refined to incorporate new information that has become available since the preparation
of the FS. These revised costs are summarized in the table below. They also are presented in
this appendix. Cost summary tables for each sub-area are presented first, followed by
capital cost assumptions, then monitoring cost assumptions.
Remediation Area
Capital Cost {$)
Net Present Value of
. Annual Cost ($)
Total Cost ($)
WQFS1 (With Heating)
WQFS2
WQFS3
EQFS
RA1A
Chena River
Total with heating
WQFS1 (No Heating)
Total without heating
$
$
$
$
$
$
$
3,610,000
1,070.000
440.000
220,000
8,000
-
3,220,000
$
$
$
$
$
$
$
3.890,000
1,730,000
950,000
1,070,000
180,000
1,560,000
3,320,000
$
$
$
$
$
$
$
$
S
7,500,000
2,800.000
1,390,000
1.290.000
190,000
1,560,000
14,730,000
6,540,000
13,770,000
Cost estimates for the alternatives that were not selected in this ROD are presented in
the FS.
ANOTRMS04.DOC/991040015
FINAL OU5 ROD E-1
-------
-------
Cost Summaries
ANC/TRMS04.DOC/991040015 . FINAL OU5 ROD
-------
-------
Table E-1
Overall OU5 Cost Summary
Remediation Area
WQFS1 (With Heating)
WQFS2
WQFS3
EQFS
RA1A
Chena River
Total (with heating)
Capital Cost ($)
3,610,000
1,070,000
440,000
220,000
8,000
-
Net Present Value of
Annual Cost ($)
3,890,000
1,730,000
950,000
1,070,000
180,000
1 ,560,000
•
Total Cost ($)
7,500,000
2,800,000
1,390,000
1,290,000
190,000
1,560.000
14,730,000
WQFS1 (No Heating)
Total (without heating)
3,220,000
3,320,000
6,540,000
13,770,000
ANC/Overal-1 .xls/983020006
FINAL OU5 ROD
-------
-------
Table E-2
Cost Summary for Chena River Aquatic Assessment Program
Biennial Sampling (Every Other Year for 10 Years)
NPV of Annual Total NPV of Annual
Year Total Annual Costs Costs Costs
1
2
3
4
5
6
7
8
9
10
$0
$350,000
$0
$350.000
$0
$350,000
$0
$350,000
$0
$350,000
$0 $1,561,607
$336,794
$0
$324,083
$0
$311,870
$0
$300.097
$0
$288,763
ANCChenarod.xls/983020008
FINAL OU5 ROD
-------
-------
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-------
Table E-5
Cost Summary for WOFS2 Selected Alternative (Alterru^ve 3)
Natural ABmuabon GroutKhntar Monitoring NnU
Pratw •wtami'Cn (rwsttd jpjupl W 20'. 40 . 60'
Activt Trwrtnwnt Sjrt***
Irvaftnert Systrm
inrtTtmwnlBlian
A' (veto
S\t Weh
Uonmnnc] »••»:
litnctmg «na Pip* tnsaUTian
Procurement and Scneai Menu*
tntiUAiUiy itudwi an tn opwmlwn and wit) b« mcofporaua MM »* RtVFU:
k WAI auumw) tut fit OW ftt)»" ma to *w AS C«ti« MXM con
me hfi ifui ASSVE OW* R*(Mn Mcauae fw n»» ol bom tftwm ***
Patwac S«e Vtat tor SyMm CtMdta
SVEM5 tyfUm O«M Hapan fjit ol OfMat)
AS CUftan OtM Ftap»n>
SV&AS sysMffl prop*
£owm ATM Mofritormg
vapor monnomg (pn>
G*oundvater mon>on
ki aAi monrtcmng o( pi
Sumurtao S
oitwifYre)
ralonno nM fYr 30)
Total Annual Cuu
NPVtf AmMlCott;
Total Catu
13.440
36.441
36,441
WOOD _
17J60
23.520
33.760
11.000
29.320
30,720
»J6C-
10.00C
1765
2U.M7
277597
UJOOJ31
13.440
M.441
36.441
30.000
.7^*0
7,840
33.710
11.000
30.720
»^80
10.000
t.7flS
237.M7
720.008
BW*>«
11440
M.441
36.441
30.000
17^00
7340
33.760
11.000
30.720
92»
10.000
1.765
237.M7
274,640
UCLiMtv
13.440
36,441
34.441
30.000
17JW
7.MO
33.760
1 1.0TO
30.720
tjeo
10.000
1.785
737.W7
220 JW
-^—^
twChtnal
13.440
36.441
36.441
30.000
17J90
7JKO
33.760
H.OPO
25.320
30.720
&2«0
10.000
i rns
767.X7
742.A07
MfWlta
5.760
16.680
19.360
*3K>
10.000
I7«5
59.06S
53.630
10 MW5
5.760
16.600
19JMO
97tO
10.000
1.785
».«5
51,«37
5,760
16.580
15.760
fl^W
10.000 10.000
1.78S 1 IK
SI. 000
1&.000
17.000
292.065 11.763
716.1X ».tt?
I
t.440 1.440 1.440 1.44Q 1.440
2MO • Z.MO 2^*0 . - 2.S40 7.HC
*.«4Q 4.440 4.640 • 4.840 4.640
19000 10.000 10.000 10000 10.000 10.000 10.000 10.000 10000 10.000 10.000 10.000 10,000 10000 10000 10000 10.000 10000 10000 10.000 10.00C
f»-
•-.TtS 1.785 1.765 1.765 V785 1.7M 1.765 1.7B5 1.785 I 785 1.7BS : TBr- 1.785 1,765 1.78S 1.785 1.765 1.7B3 1.785 1.765 1.785
—
10.SOC
30<2S 1T,7fr^ lt.7«S 11.785 11.785 S0.4J5 1J.785 11.765 11.785 11.765 70.475 11 785 11,785 11.785 11.785 20.475 11785 11.785 11.78S 11,785 30.92S
't*5l t.536 »J56 9.178 9.003 1S.X7 8.603 0,49« 8336 8 178 13.903 7 669 7.719 7,57? 7,429 12.629 7.14ft 7.012 6J7ft 6.747 17.361
-------
Table E-6
Cost Summary (or WQFS3 Selected Alternative (Alternative 3)
DmctCaMUICMU
KatunJ Attenuation Crwndwltst Monherma New
»4I20 40-.W]
Utnt TnMnent SyiHlf
H
740T
iev.'
riwum-jmjiicn
AS Well
SVC Wdi
ItoMOfwg »*cij
Tiencfemp and PC* leHUIar-an
PiDcmr^ i-**l and SctctxAng
Mobhiaton
EmVng tucl pip-time (»97«Q
trttdnc UUrty Corwtdions aod As-tu-lu
lnil.tIUt.Dn Oytrtiflht
Buckne Sampling and Startup Teitc,;
5*9 Refiorftien ;wd Off-nob
Ctoiwt •nd Dteommlufontiig
D*com«w«)n eMjhng w-ets end prates
Tot* Dmct CatpiUI Cosu
is r>- .
Ab.O
uoo
10.800
J3.7SO
20-000
20*»
20.000
12.025
1500C
33.00*
12500
265,475
31.WO
S 310175
Th« SMctttf Atttmatrvt (AtttmMrv* 3) fof WOFS3 Kj
Hot !>pQl 7reair>#nt «r>m So* V»po* EwactKXt and An Spaing. tntbMnnil Conirott. »fv3 Morworttland tvikiaied Natgrai A
ttwri Mt curnnUy no bialabil-v *tudnt.
Alum* ttw loUowtnfl trcttmcm tytltira Mt not ewraoUy inaUltod but will tw buulltd •• part o< UM
1 HoopotAS/SVE
induct Capita* Corti
(10% of Omct C»{xul Ccnt»:
Engi>Mi»ig. kuMuWn«J Control Purvwg
rwunt Mtmuabon Pragnm Pnm»fl
•Fnwvw>g(ixD«CQnvnj««Kning
Engn-ttnng Modrly Fort Wa*nwngh| ConKX«...ir.*M Plan
Ucao-M M-K) Cofnkeymc-i:
Ctvttngency (15^ of eap-W)
Tot..llndtf«aC.»pH4ilCo«t»
M7
1*40
11.050
4.9S4
eo.ose
S 1M.587
ToM 04r«ct and Mdtftct Capiul Cosu
OgarHkifmnd HUInttmnct Com
year
«We«lon«« |
c
Qpecauxi ol Active Ttetimem System
Peno*c S« Vrtrts tor Syslem Ctwoxs
AS SVS OtM Bepajn (5X ot capttl)
SvE/AS system propane
Source Area Kontorlng
Prefect Uanagement and Field Coorr>natxxi
Vapor monnonng (ore- and post- otlgas)
GrounOwete* monMonng mtrun Source Area
In srtv morwlonng of physical parameterl
Subsurface Sol sampling (baseline and confttmalion)
Reporting
«atunt Anenuatton Monrlorlng and kislitulionai ControU
Natural Attenuation Uonnormg
Institutional Controls
(5% 01 cacul costs prorated lor » years)
Ctosw. tna Deeommssiomng Cotta
Closure sol aamptng (YrB)
Oecommsson source _ J9 30
1.080 • - 1.080
1.920 1.920
3.690 3690
5.000 5.000 5.000 5.000 5.000 5000
734 734 734 734 734 734
7.500
12424 5734 5734 5 73* 5.734 12424
7.682 3478 341? 3347 3283 R978
ci StmT».yM3a.>OOTi
-------
Tame 6-7
Coit Summary for EOFS Seleettd Attematlv* 'Attemaltve 2)
Institutional Controls:
insUJJH.gr.VrsiW'iyS'onj
Natuta! Attenuation Groundwalar Honftoting Nests
Prow insulation (nested gtouer at SO". <0'. 60'
Ac;«t*e Treatment System
fc using luel pipeline p«wnf (behxe system install;
Procurement, scheduling, ana permtntng
IrutaK'OeveKtp rtonzonui AS wets
Inuiiioevctop vcn-calSVE w«Hi
InttaH conveyance piO*^ . sei connex. and connect
Elecincal hook up and a»-bwb wrvey
instaH rrromlofmg nests (groundwau ' and vadose)
Site restoration «r*0 d^mobtbiatior
Basekne wnpling and siartop WStwg
Ckn.ui- and OecOfnmliswnirig
bcL>XTMiiiS$ton emstng wrts and probes
Total Direct Ca«Hal Costs
Cost
16.905
53.5)7
90.106
$ 160.S30
Enginmirig (10% of Dtncl Capjul Co«u):
Engneeflng- bumutxxul CeMrol Plmwlg
En^ntonnff Natudl MMnuahon Program PUmwg
EngAMimg' Active Tiwtmtnl SysMm Destgn
Enffrninog : PUnnmg tor DflCOflvrMaxvMng
En^ntnq MoOly Fon WwwmgM Conpnteww Pl«l
Lk«tM Md CoMlngwey:
Lk <6% insuXM eipul costs)
Co (ISXeapul costs)
Yom mcund C«pHal Costs
row MM «nel kidlncl Csolul Cora
1,«91
SJiZ
1B.1I1
7.055
IM94
37.O5
t 57.676
S 218 409
The Selected AltemaHw {Alternative 2) lor EQFS te:
Continued Operation ot the BuMmg 1060 SVEMS TfeataMity SluOy System. Imlriuftona! Coniroli. and Monnofea and £vaKOied rJatu*«l Anenuahon
Assumes the to!towing irtataWttty tlucUec are in operation and will be tneo«po**tedlrrto the BORA.
t Buddmq1060SVE/AS
AssumN no «hHUon*t treatment systems will be hutatled as part of the RORA.
0= . ^j-—
WMtoml_
c.
Op««(iun et Aetiv* Tmtmnl Systim
f«nodc S4« ViMs lor System Check*
BuWog 10W TS OiM RepWS
Sowet Art. Monitoring
Project Management
Vapor momtonnfl (pre- and posl- oflgas)
&ound«*aler montonnr) wtttwi Sourca Are*
tn vtu momtanog of physical pinjmeler!
Subsurface Soil sampling 'tMsetne »t*i eonftrmalion:
neoornng
Nstural Antnuatton Monilortng and kwutuuonai Control*
Natural Attenuation Monrtonng
trtstrtutional Controls
Uaimanance Funwrv* Fund (Contingency)
(5* ot capital costs prorated for 30 yean)
Closure loJ lamphng (Yr8)
DKominssion source area Busang 1060 TS (Vi 8)
DaojmmissionNAmon«oringn«sl|Yr30|
Annual Costs
NPV of Annual Costs
ToM NPVo) Annual Costs J
TMMCosts t
1.
Contr
1
MdOpar
9 4
bon ol BKtQ tOW T
S
> 1
..'..
Benzene MCL met n «» Chena River
-------
r
o*
^
I
s
a
3.
-------
Direct Capital Costs
ANOTRM5M.DOC/9910400,5 FINAL OU5 ROD
-------
Table E-9
Direct Capital Costs for WQFS1 Selected Alternative (Alternative 5 with Heating)
f
WQFS1 Cost
Item
Natural Attenuation Well Installation
Treatment System
Instrumentation
Horizontal AS Wells, Total Feet
SVE Wells
Monitoring Wells
Trenching and Pipe Installation
Procurement and Scheduling
Mobilization
Existing Fuel Pipeline Pigging
Electric Utility Connections and As-builts
Installation Oversight
Baseline Sampling and Startup Testing
Site Restoration and Demob
Decommissioning Existing Wells
Total
Number
12
1
1
3037
16
18
1
1
1
1
1
800
1
1
1
Unit Cost
$ 2,400
$569,302
$132,150
$ 90
$ 1 ,400
$ 1,800
$157,500
$ 80,000
$ 40,000
$ 20,600
$ 38,700
$ 75
$149,700
$ 89,500
$ 43,800
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
Total
28,800
569,302
132,150
273,294
22,400
32,400
157,500
80,000
40,000
20,600
38,700
60,000
149,700
89,500
43,800
1,738,146
*
*
*
*
Notes:
Standard monitoring wells are assumed to be 30 feet deep (average) and S60/foot (S1,800 each).
Natural Attenuation monitoring wells are assumed to be 40 feet deep (average) and S60/foot
(S2.400 each).
All monitoring wells are augered.
Air sparging wells are driven.
SVE wells are augered.
The treatment system includes the connex, blowers, actuated valves, motor starters, switches, PLC
system, and catalytic oxidation / thermal treatment system for off gas.
Includes capital and operating costs for the air sparge trench.
Includes capital and operating costs for soil heating.
Capital costs are not included for the Hart Crowser TS or the DO 17 TS. However, operating costs are included.
Costs for the.AS/SVE treatment systpm are based on scaling up the DO16 connex based on area treated.
* = Taken directly from Final OU5 FS with no change
ANC/Wqf 5 1 htg,xls/983030009
FINAL OU5 ROD
-------
Table E-10
Direct Capital and Operating Costs for Soil Heating, WQFSt
Item
Direct Capital Costs
Install heating wells
Set structures and complete connections
Install heating and monitoring points
Mob and demob
Subtotal
Operating Costs
Heating System Monitoring
Labor
Equipment and materials
Quarterly reporting
Routine Maintenance
Heating system maintenance
Maintenance reserve fund
Subtotal
140
: 1
1
1
WQFS1 Cost
$ 800
$ 26,000
$ 30,000
S 90,000
ea.
LS
LS
LS
WQFS1 Cost I
Total Quantity Unit Cost Unit T«f-.i
$112,000
$ 26,000
$ 30,000
$ 90,000
$258,000
Year 1
52
12
4
• 1
1
$ 4,000
$ 47,300
$ 5,000
$ 10.000
$ 10.000
week
month
quarter
LS
LS
$208,000 52
$567,600 12
$ 20,000 4
. $ 10,000 1
$ 10,000 1
$815,600
• '• 1
Year 2 ' I
S 4,000 week S 208.000
$ 47,300 month $567,600
$ 5.000 quarter $ 20,000
$ 10,000 0 $ 10,000
$ 10,000 0 $ 10,000
S815.600
Assumes a two-year heating period. Hall the area is treated the first year and half is treated the second year.
A total of approximately four acres is treated over the two-year period.
ANC/Wqfs1htg.xls/983020009
FINAL OUS ROD
-------
Table E-11
Direct Capital Costs for WQFS1 Selected Alternative (Alternative 5 Without Heating)
f
WQFS1 Cost
Item
Natural Attenuation Well Installation
Treatment System
Instrumentation
Horizontal AS Wells, Total Feet
SVE Wells
Monitoring Wells
Trenching and Pipe Installation
Procurement and Scheduling
Mobilization
Existing Fuel Pipeline Pigging
Electric Utility Connections and As-builts
Installation Oversight
Baseline Sampling and Startup Testing
Site Restoration and Demob
Decommissioning Existing Wells
Total
Number
12
1
1
3037
16
18
1
1
1
1
1
800
1
1
1
Unit Cost
$ 2,400
$569,302
$132,150
$ 90
$ 1,400
$ 1,800
$157,500
$ 80,000
$ 40,000
$ 20,600
$ 38,700
$ 75
$149,700
$ 89,500
$ 43,800
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
Total
28,800
569,302
132,150
273,294
22,400
32,400
157,500
80,000
40,000
20,600
38,700
60,000
149,700
89,500
43,800
1,738,146
*
*
*
*
*
Notes:
Standard monitoring wells are assumed to be 30 feet
deep (average) and $60/foot (81,800 each).
Natural Attenuation monitoring wells are assumed to be 40 feet deep (average) and $60/foot (52,400
each).
All monitoring wells are augered.
Air sparging wells are driven.
SVE wells are augered.
The treatment system includes the connex. blowers, actuated valves, motor starters, switches, PLC
system, and catalytic oxidation / thermal treatment system for off gas.
Includes capital and operating costs for the air sparge trench.
Includes capital and operating costs for soil heating.
Capital costs are not included for the HattCrowser TS or the DO 17 TS. However, operating costs
are included.
Costs for the AS/SVE treatment system are based on scaling up the DO 16 connex based on area
treated.
• • Taken directly from Rnal OU5 FS with no change
ANC/Wqls1 woh.xls/983020007
FINAL OU5 ROD
-------
Table E-12
Direct Capital Costs for WQFS2 Selected Alternative (Alternative 3)
WQFS2 Cost
item Number Unit Cost
Natural Attenuation Well Installation
Treatment System
Instrumentation
AS Wells
SVE Wells
Monitoring Wells
Trenching and Pipe Installation
Procurement and Scheduling
Mobilization
Existing Fuel Pipeline Pigging
Electric Utility Connections and As-builts
Installation Oversight
Baseline Sampling and Startup Testing
Site Restoration and Demob
Decommissioning Existing Wells
Total
9
1
1
53
3
8
1
1
1
1
1
600
1
1
1
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
2,400
215,400
53,850
500
1,400
1,800
141.250
40,000
35,000
20,000
36,725
75
84,000
12,500
20,000
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
Total
21,600
215,400
53,850
26,500
4,200
14,400
141,250
40,000
35,000
20,000 *
36,725
45,000
84,000 *
12,500 *
20,000 *
770,425
Notes:
Standard monitoring wells are assumed to be 30 feet deep (average) and $60/foot ($1,800 each).
Natural Attenuation monitoring wells are assumed to be 40 feet deep (average) and $60/foot
($2,400 each).
The treatment system includes the connex, blowers, actuated valves, motor starters, switches. PLC
system, and catalytic oxidation / thermal treatment system for off gas.
* = Taken directly from Final OU5 FS with no change
Costs do not include capital costs for air sparging curtain, but do include operating and
maintenance cost for the curtain.
ANC/Wqfs2rod.xls/983020010
FINAL OUS ROD
-------
Table E-13
Direct Capital Costs for WQFS3 Selected Alternative (Alternative 3)
WQFS2Cost
Item
Natural Attenuation Well Installation
Treatment System
Instrumentation
AS Wells
SVE Wells
Monitoring Wells
Trenching and Pipe Installation
Procurement and Scheduling
Mobilization
Existing Fuel Pipeline Pigging
Electric Utility Connections and As-builts
Installation Oversight
Baseline Sampling and Startup Testing
Site Restoration and Demob
Decommissioning Existing Wells
Total
Number
6
1
1
9
1
6
1
1
1
'1
1
200
1
1
1
Unit Cost
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
2,400
74,000
18,500
500
1,400
1,800
23,750
20,000
20,000
20,000
12,025
75
33,000
12,500
31,000
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
Total
14,400
74,000
18,500
4,500
1,400
10,800
23,750
20,000
20,000
20,000 *
12,025
15,000
33,000 *
12,500 *
31,000 *
$310,875
Notes:
Standard monitoring wells are assumed to be 30 feet
deep (average) and $60/foot ($1,800 each).
Natural Attenuation monitoring wells are assumed to
be 40 feet deep (average) and $60/foot ($2,400
each).
Monitoring wells are augered.
Air sparging wells are driven.
SVE wells are augered.
The treatment system includes the connex, blowers,
actuated valves, motor starters, switches, PLC
system, and catalytic oxidation / thermal treatment
system for off gas. . .
* = Taken directly from Final OU5 FS with no change
ANC/Wqls3rod,xls/983020011
FINAL OU5 ROD
-------
Monitoring Costs
ANC/TRM504.DOC/991040015 RNAL QU5 ROD
-------
-------
Table E-14
Monitoring Costs for VVQFS1 Selected Alternative (Alternative 5 with Heating!
Sampling and Labor Assumptions
Operation ol Active Tnutnera System
Monnuy Site Visits tor System Clucks
Source Area Monitoring ~
Protect maraowntm and lidd cwxdmation
Vapor monftxino. (prt- and post- otfgas tMtngnt)
GiotnXMtm monrtomg Mttun Soutc* AIM
In »tu monitoring ol physical parameters
Subsurface Sol tamping (bnatne »x> confir Cost Cost Toul
Y«rs3lo5 4 $6.720 $C.720
Years 3 to 5 4 K.uo $a.MO
Y
-------
Table E-1S
Monitoring Costs lor WQFS1 Selected Alternative (Alternative 5 without Heating)
Sampling and Labor Assumptions
Monmiy Site Vrs« lor System Checks
Source Area Monlonng
Proract manayernem and I»W cooroVulion
Vapor montonng (ore. and posh orlges treatment)
Grcurxhralet monunng wttrun Source Area
In iitu monrlonng ol physical parameters
Subsurface SoJ sampfcng (baseline and contirnutnn)
Reporting
Natural Attenuation Uontonng
Natural Anmualon Montonng
Anatysis
Samples cost per Labor Hours labor Rate
perevenl samplelS) perEvtnt perhourCS)
20 S7C
24 $90
1 1350 e $70
11 $600 102 $70
12 $3.000 108 $70
96 MO
1 $600 57 $70
Tout Total
Events Analysis Labor
Time Period per year Coil Coll Total
Years IMS 12 $16.800 $16.601
Years 1lo5 12 $25.920 $25.820
Vearl 12 533.600 56.720 $40.320
Years 1 10 5 4 $43.200 $26.560 571,760
Years llo 5 $44.000
Yearl 1 $36.000 $7.560 $43.560
Years 110 5 12 $34.550 $34.560
Years 1»5 2 $10.800 $7.860 $18.780
Total
Events Analysis Total Labor
Time Period pel year Cost Coal Toul
Vears6»8 _4 $5.600 $S.60&_
Years 6 10 6 4 S8.640 $8,640
Years2K>5 4 $11.200 $2.240 $I3.*4J
Years 6 toB _2 $21.600 $t' 280 i35.S80
Y«"5 1 $36.000 $-560 $43.560
Years 6 to 8 2 $10.800 $7.980 $18.780
Tolal
Events per Aruh/sls Toul Labor
Years 9 to 30 2 $2.800 sj.600
20,25.30 t 5;,i60 52,160
20.25.M 1 55.400 53.990 59.390
Bold number; ndcate •» parametera B* vary by Suc-erea
Aaaurnptiont:
Protect Management tin* a*tume> 24 ha per montx hnh* monlr* *«>g YMr» 1 Bi.kwrromoVrr^ Yejiri 10.15.20.25.»nd30.
Vapor MtxMoring auumn 2 unplei ucti hom howonttl treJI TS. run Grower TS. Source a>uTS.ardli«a«ax>ie>Rialedun«r Via ROTU (4 loea^utal).
Groc»i*«ateri«lrtaluimlAn»i«alicoltoi«x»ioljJxr. imi atari to aimple. 2.5 ho pet sample. 4 m mooMemt*, 8 hn lab coordnatnn and data marogement.
Si*»urlacefoil««np*nrj- Numlwolia
-------
TabIeE-16
Monitoring Costs tor WQFS2 Selected Alternative (Alternative 3)
Sampling and Labor Assumptions
Operation ol Active Treatment:
Monthly Sue Visits lor batem Checks
Source Aroa Monitoring '
Project mwwgemenl and Wo coordination
Vapor nxmtonng (prt- and po«. cffgas toainant)
GroundwaMr monitomg within Source Area
BI irtu fnonitaring of physical patamMen
Subsurface Soil sampling (burtne and conttmatan)
Raporting
Natural Ananuaton Montonng" - - —
Natural Anenuaien t
$350
$600
$3.000
16
8
52
76
32
$90
$70
$70
$70
$80
YurslloS
Ycarl
Years 1 US
Yaars < ID s
raars 1 and S
fears 1lo 5
12
12
4
1
12
_$13.440 $13.440
$17.280 $17.280
$16.800 $6.720 $23^20
$18.200 $14.560 $33.760
$11400
$24.000 $5.320 $29,320
$30.720 $30.720
tow numtwrs «*cale tw pmntatns lul nry tjy Suturaa.
Alsumptioni:
$5,760 $5.760
$5.600 $2.J40 $7.840
$9.600 $7.280 $16.880
"""•"^
$1.440 $1.440
. S2'56?.. .«.560_
$2.400 $2^40 $4.640
*MCAVq(»2roa.«lus«3020010
FINAL 0115 ROD
-------
Table E-17
Monitoring Costs for VJQFS3 Selected Alternative (Alternative 3}
Sampling tnd Labor Assumptions
MonNy SHI ViMs lor Syirtm ducks
Sourc* Ant* Monrtonng
Project management and fi«W coorolnalion
Vapor monrtonng {p/«- and post* oflgas fraatnant)
Groundwalar monitoring witiin Scute* Area
In utu monitoring of physical parameiari
Subwrbea Sol sampling (basa&M m confctniton)
Reporting
Natural Attenuation Monitoring
NaturU Atnnuatnn Morttorhg
Anifyits
Sample* cmtpar Labor Hours LaborRrt*
ptrmtnt Mmptart) p*rEMn< pwhourrs)
1 »0
12 $30
2 S3SO 8 SA>
E SeOO 42 JTO
( 13.000 75 J70
24 sao
3 MOO 27 $70
TVUI TOM
EvtnU Anirfilt Ubor
T1m«P»rlS 12 $23.0<0 S23.0W
Yunttua 2 $3.600 S3.7BO S7.3W
Todl
Ewnu Anilyib ToMlilMr
TVntP«riog«n«i( timt auuntt • I hrs per monlh; nwhw momhj during Y«»r« 110 S. •ixrnvinhteurk^YnnKloB.ardcnerinnliduringYMrilO. 15.20.2S.and30.
Vapor Monrtoring assumes 2 samptas from ln« connax instalad during tti« RO/RA.
Groundwalw and Natural Anonuatnn Monitoring Labor twstattusan^.£5rnc«iafl*fe,4lnr«c4borir^tob»in>taB«d: cofl par boi^ iridudn corahoto advancvmant. lanxto o*xtk». art
Subsurfaca sod sampling Labor. MM aaff lo sampl«, 4 hrs par borehoH. 4 hrs mob/a*mob. a hra lab and subconttaclor cooninaiion,«nadattmanaa«m»nt
« assumes 24 hn> p« monti; tMhw moraht during Yaara 1 to 5. sin ^«1(h^c^lr^YeaoI6)o^^r«Jo«fTlon^h^^u^ingYaar»10.1S.20.2S.and30.
ANC.Wqls3rod xlsflaSCBOO11
FINAL OU5 ROD
-------
Table E-18
Monitoring Costs for EQFS Selected Alternative (Alternative 2)
Sampling and Labor Assumptions
Montfiiy Site Vote lor System Checks
Source Area Montotag
Proud management and Wd coontmton
V«p.i... «_ _.. . S3.360 . $3.360 _
YMre1IDS « $6.480 $6,480
V*ac1 < SZ.BOO $2i40 $5.040
Yaai»1to5 4 $19^00 $14^60 $33.780
VaarsltoS ^j^
YMr1 1 *1».000 $4.200 $22^00
Y^^1I°5 2 S4.800 $4.480 S9.MO
t- . _ —
Total
Ewffli Analysis Total Labor
Tlm« Parted ,»,„„ ,-„, CMI Tou|
YMfs6loB 2 $8i600 (7iBO $16B80
Y*"S ' $18.000 $4.200 $22^00
I?!?.6.10?.. . .«... J."..520 $11,520
Total Total
Ptryiar Cost Cos' TMal
" ' ' ' _
' $1.080 $1.080
. ' S1.920 $1,920
1 52.400 $2^40 $4640
AsrampOani:
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FINAL OUS ROD
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